I would have accepted healbot if it was just letting me see my mates hps and also the timers for my heals and let me do the rest by myself
Healbot had already long since been broken by Lich King so I have no idea what you are talking about here. That's all it does - let you see HP and some status ailments in the raid frame and you do your healing based on that. Yes, it was broken when it first released. Blizzard stopped that, and now it's just a convenient and useful add on like Grid+clique. Some prefer one, some prefer the other, and some use the default raid frames, but they all serve the same purpose and it's down to what you prefer.
As far as your other comment regarding too many add ons... Well you do realize that millions upon millions of people play WoW, right? Higher percentage of folks with programming experience + diverse desires for ease of information display= lots of adds on and people developing them. So what if there are 10k add ons? as a percentage versus 9+million people playing the game over the course of the last decade, that's pretty tame. All that shows is that people are interested in add ons and they add tremendous
value to mmos.
I'm hoping for a robust enough API to at least have add ons like bartender and healbot. I like my UI in a very specific pattern and I like to be able to keybind my mouse buttons to cast spells. Currently WoW is really the only game out there with an API robust enough to make things like that happen. Even Rift, which boasted lots of functionality right out of the box has a nightmare of a UI that constantly does whatever it wants regardless of where you put things. Stuff like that is just better outsourced to the players, so the devs can focus on more important things like developing content, encounters, and hiding treasure for us to find. There's no way that they will ever be able to put together a one size fits all UI, so why even try? Keep it basic and say, "here's a programming kit, good luck!"
Then if something is developed that SE thinks is too exploitive or automates things, they can break it like Bliz does.
Add ons just add too much value and are too important in this age for SE to ignore. The more accessible the game is, the better chance it has of great success.