On the total opposite of this, I can only raid if it's completely planned since I have significant partner agreements for playing on certain days, for certain time stretches. If it's 'on the fly' I can rarely join in. Family aggro ensues if there is considerable 'overage'.

Anom, it's also fair to point out that some people don't have the additional time it takes to fund regular raiding, not to mention gems/enchants. Incoming wall of text example.

I have a friend who works second shift, averaging 10 hours a day, 5 or 6 days a week. He doesn't have time to jump on WoW and run a few dailies, or jump on WoW and do some farming. When he gets on WoW, he wants to spend his limited time doing something fun, and sometimes that means dailies or questing, and more often that means running heroics or BGS or trying to PuG a raid. (Me, I hate dailies, so I sympathize with him.) So the upshot is that he has every piece of Conquest badge gear he can get and the rest of his slots are full of T7 pieces he's picked up in PuGs, and he doesn't have enough income to enchant and gem his not-so-amazing gear to the max. He's also only exalted with tabard factions, isn't a champion with the Tournament, and the last few times he got on, I know for a fact that he was working on the Wrathgate quest chain rather than grinding... whatever. And he WON'T grind... whatever... unless it's fun because he doesn't have time for it.

Now, I will say that I love running with this guy. He knows his class inside and out, has a great eye for tactics, and uses every tool in the mage toolkit. (Yes, all three colors of fireballs. :-D) So the guy's got skill. But his enchants... well, he's a scribe, so he has a great shoulder enchant, and he has the head enchant, and his Turning Tide, of which he is quite proud, has the best weapon enchant because he splurged after getting it unanimously awarded to him on a PuG. (Yes, he is that good. That and the holy pally had already won a bunch of stuff. :-D) Other than that, his enchants are the low-budget version or don't exist. His gemming is top-notch in terms of what he prioritizes, but it's only about half epic gems. This is because he doesn't have time to spend grinding rep/money.

I'd go with him to any raid he was geared for any time, and he likes raiding, but ToC10 is pushing it for him, and he knows it. He might raid with a weekend guild if he tripped on one that he liked, but even if a casual guild that raided at 2 AM a couple of weekdays and normal times weekend evenings and that didn't mind if he didn't show because he stayed at work late or got called in recruited him, he doesn't have the extra time to spend grinding and farming to get the enchants and gems and repair money and flask money and get his cooking and fishing leveled for high-end food and so on. And while he likes raiding, he HATES being carried... wants to feel like he's contributing... so he'd never sponge all that stuff off the guild unless it provides those things for everyone, and I don't know many guilds that do that... certainly none that are just weekend raiders. So while he meets your criteria of someone who could totally raid, based on his skill, he flat does not have the time for any sort of regular raiding, and this expansion is moving too fast for people like him to keep up by only running one or two raids a week.

TL;DR: Skill goes a long way, but there are, in fact, minimum time requirements for raiding.

Anom, it's also fair to point out that some people don't have the additional time it takes to fund regular raiding, not to mention gems/enchants. Incoming wall of text example.

I have a friend who works second shift, averaging 10 hours a day, 5 or 6 days a week. He doesn't have time to jump on WoW and run a few dailies, or jump on WoW and do some farming. When he gets on WoW, he wants to spend his limited time doing something fun, and sometimes that means dailies or questing, and more often that means running heroics or BGS or trying to PuG a raid. (Me, I hate dailies, so I sympathize with him.) So the upshot is that he has every piece of Conquest badge gear he can get and the rest of his slots are full of T7 pieces he's picked up in PuGs, and he doesn't have enough income to enchant and gem his not-so-amazing gear to the max. He's also only exalted with tabard factions, isn't a champion with the Tournament, and the last few times he got on, I know for a fact that he was working on the Wrathgate quest chain rather than grinding... whatever. And he WON'T grind... whatever... unless it's fun because he doesn't have time for it.

Now, I will say that I love running with this guy. He knows his class inside and out, has a great eye for tactics, and uses every tool in the mage toolkit. (Yes, all three colors of fireballs. :-D) So the guy's got skill. But his enchants... well, he's a scribe, so he has a great shoulder enchant, and he has the head enchant, and his Turning Tide, of which he is quite proud, has the best weapon enchant because he splurged after getting it unanimously awarded to him from a PuG. Other than that, his enchants are the low-budget version or don't exist. His gemming is top-notch in terms of what he prioritizes, but it's only about half epic gems. This is because he doesn't have time to spend grinding rep/money.

I'd go with him to any raid he was geared for any time, and he likes raiding, but ToC10 is pushing it for him, and he knows it. He might raid with a weekend guild if he tripped on one that he liked, but even if a casual guild that raided at 2 AM a couple of weekdays and normal times weekend evenings and that didn't mind if he didn't show because he stayed at work late or got called in recruited him, he doesn't have the extra time to spend grinding and farming to get the enchants and gems and repair money and flask money and get his cooking and fishing leveled for high-end food and so on. And while he likes raiding, he HATES being carried... wants to feel like he's contributing... so he'd never sponge all that stuff off the guild unless it provides those things for everyone, and I don't know many guilds that do that... certainly none that are just weekend raiders. So while he meets your criteria of someone who could totally raid, based on his skill, he flat does not have the time for any sort of regular raiding, and this expansion is moving too fast for people like him to keep up by only running one or two raids a week.

TL;DR: Skill goes a long way, but there are, in fact, minimum time requirements for raiding.

Man, a wall of text comment is a bad one to hit WoW.com's fail comment system. Now I feel like a right proper ass.