Add ons are still quite functional in this game. It is true that they removed some functionality that was there previously. The two most noticeable are buff/debuff trackers and cast bars.
However, I've seen quite a bit of misinformation beyond that. Some people are under the impression that things like Scrolling Combat Text, DPS meters, HOT meters, and even information about your own resources has been removed. If that were the case, the term "gutted" woud indeed be quite apt. But all of those things, plus a lot more, are still in the game.
The misinformation surrounding the API changes is pretty massive. Even on the closed Beta PTS, a lot of people were confused about what was going on. I believe this is contributing to some of the emotion and high tempers surrounding the issue. Thankfully, a PTS poster by the name of MrDDT showed up to demonstrate that most functions of the Foundry Tactical Combat mod, plus several other mods, are still quite functional.
http://i38.photobucket.com/albums/e107/MrDDT/Royalty%20Gaming/Screenshot_20140320_210002_zpsc19d55d3.png
Now, personally, with all of that information included and still available through the API, I think its a stretch to call it gutted. But, I fully understand that some people may have a difference of opinion with me on that subject.
My main purpose wtih this thread was to spread information, since most people don't seem to know exactly what was taken out. I don't much want to engage in the debate myself, but with that said, lets remember that we can discuss difference of opinion without resorting to personal insults and flaming. This is a video game. There's no reason to be rude to each other just because we disagree. No one should have to be reminded of that but a moderator asked me to mention it since prior threads were closed due to flaming.
What you can see in the photo:
-Scrolling Combat Text for damage dealt, including ability names.
-Exact numbers on all of your own resources.
-Exact numbers on your enemy's health.
-Percentages and exact numbers on your ultimate resource.
-A MINI MAP (bolded because people have asked for this since ZOS removed it.)
-Damage Per Second from your last fight.
-Healing Per Second from your last fight.
-Your Frames Per Second.
-A Clock.
-Your current XP and XP to next level.
-How much gold you have without opening your inventory.
-Some other stuff.