Exactly.

All people did was complain that heroics (and many raids) were worthless and easy and elementary from launch. Even the more-casual people were getting bored of "faceroll aoe" heroics. TotalBiscuit said it best when he was doing the Cata-event bosses on the PTR: "It started easy and it ended easy".

So Blizzard listened and made them legitimately difficult. I wouldn't call heroics really BC difficult (especially now that average gear lvl has gone up), but significantly more difficult than Wrath. Which is what the majority of players wanted, right..?
While I think that the difficulty from boss-to-boss could have been much smother (something they adjusted), I felt like Heroics were actually pretty much spot on in difficulty. It took some focus and some effort, yet only a couple times did I feel completely helpless/frustrated, and those moments were overcome with some better gear and better flexibility.

Honestly, my only issue with heroics is that they were too damn long and the random nature of the dungeon finder means I'm screwed if I only have an hour to play and I get DM or SFK. I've heard Blizzard say "we hear you on the length" but I'm concerned that ZA/ZG (which were originally raids) will take 2 hours each as well.