Yah, that's just you.

It's all a matter of degree. You accept (as useful or legitimate) the input we get from the default UI, but even there you have choices in how you set your interface options. Addons like Healbot that modify what information you see, and what you need to do to perform various actions are just, well, additional. Additional interface choices. When you look at how many official interface changes have their roots in addons, you can see that Blizzard feels the same way. For example, patch 2.4 will internalize a bunch of the stuff that Omen does now.

I loves me some good addons. Even though TMA tells me I'm a wuss for only having 79 of them running...

Exactly.

If you want an addon telling you when to push a button. The only input I want to see is if the tank's health staying above 1. Anything else (to me) is overkill. I understand if ppl need some help in doing so.

79 addons? That is a lot of addons.

Yep, it's just you!

Addons are meant to enhance the experience and take a lot of the otherwise unnecessary crap out of maximizing your performance in this game. You don't have to use them. Most of them don't tell you when to do anything at all, you're still up to your own intelligence level as to when and why you do things. They just offer a helping hand, or one less step or a much better look at things.

For example, it's a proven fact that your eyes and your brain work better when they have to do less work. If the important things you need to watch all happen in the same portion of the screen, you're much less likely to miss things that are important. This is why a lot of people dislike the built-in Blizzard unit/raid frames, as they're honestly in a pretty terrible location and aren't very informative and for the most part that's one of the most important things to replace. Your eyes have to go all over the place to use them, and that's going to cause eye fatigue and you've got a pretty high chance of unintentional mistakes or not noticing changes in your game environment if you're looking at the upper left corner of the game rather than somewhere approximately in the middle.

Blizzard designed their interface to be able to take advantage of the innovations that other people can come up with. It's the new way of thinking, collaboration with everyone rather than closed design is a much more productive way of working. Blizzard gets to focus on the important things of making sure the actual game works, and lets the community figure out how they'd like it to be represented. Blizzard has the full ability to shut down any addons they want at any time whatsoever, so it's silly to not take advantage of them for the most part. Some people go overboard of course, but there are a lot of very good reasons to use good addons that enhance gameplay.

Blizzard's default UI is meant to be changed. It's really the reason the game is so popular I think. Lots of people would quit and get frustrated with an interface of a game far more quickly if they couldn't customize it and remove the limitations they feel are inherent in the system.

i personally think that most of the people who are addon resistant are probably much worse off in the game than those who embrace at least a few of the more helpful ones.