The main author of DBM thinks addons are indispensable and everyone should play with them? He also thinks it's fine if addons are that powerful? What a surprise. No conflict of interest at all here
Outside of a few exceptions(raden assist and that kind of stuff), addons are a simple comfort. You heavily underestimate what players can do if you think addons are anything more than that. The WoW community isn't suddenly crippled on beta when addons don't work. Performance goes down a little, mostly because people have to adjust to the change in UI more than anything else.
The only thing that truly sucks in the base UI is their implementation of raidframes. Everything else is totally unnecessary and you really don't need to look at db/bigwigs timers to play bosses correctly. Back when I used to raid I disabled most of them anyway because they're just unnecessary clutter for the most part. The few timers remaining are simple comfort (and/or already have some warning in the base UI), nothing a simple clock and a bit of common sense can't do.