Remove all addons

[Kalmah]

No one NEEDS addons. However you can't dispute that some addons make things easier, so why not use them ? Sure you can perform well without addons, but you could probably perform even better with a more optimized UI.

Recount certainly isn't a mandatory addon or even something that will help you improve. The only point I see in running it at all is for things like death logs. I don't really get why knowing how much dps / hps you do would be useful. Most guilds run WoL or WMO parses for that anyway.

[ComputerNerd]

Some players read bars more quickly and easier than they do text, and therefore a threat meter like Omen is a perfectly valid option for them.

Damage meters, if used properly are a quick analysis you can do between pulls and see if there is something immediately wrong that needs addressed.

Manipulation/Movement of the UI elements make for a more natural positioning of the information you need to know, which with good reason is why virtually all compilations have unitframes in a centralised and often lower or bottom position.

Actionbar buttons and the sweep animation which is very difficult to read in a hurry, enhanced by adding numbers from OmniCC.
Quantities of possible timers to watch make even numbers on the buttons potentially awkward so timer/alerting addons such as PowerAuras, TellMeWhen, NeetToKnow etc are offering an alert or timer setup where you can choose to see what you want to know about, and not what you don't.

Boss Mods are what encounters are actually designed around now, so refusing to use them makes you an idiot, and really complaining for the sake of complaining.

Your dislike of addons is evident, but I am instead of seeing valid arguements just seeing criticism of those who choose to use them, who in many cases as I have described to be more selective and improving the display of information which the default UI does badly.
All I see is a spoilt kid who thinks because he does something different it makes him better, when all he is doing is refusing to use the tools availalable.

[Cyriaa]

For heroic raiding, you're going to NEED an addon with timers. (DBM has them).
For example, Searing flames on atramedes.
If nobody is using addons, by the time he emotes you get on tic, you move to the gong, 2 tics, by the time you get to the gong and click it, 3 tics raid is dead.
What they're saying when they say your UI is too clean is that you're using the default blizzard UI (which imo is terrible). But by no means is something that is required to change. You can still use it in raids.

[Xuany]

I used to use quite a few addons, then I ended up going back to default with only a handful of addons. Omen, OmniCC, Grid, Clique, JS' Hunter Bar, Needtoknow. My addons for my entire account atm, that's all I really needed anything else was extra to make it look nice, looks fine with default.