Okay, okay, I'll try to play Devil's Advocate here. Someone has to.
Well, first off...uhm...see, there's...
You realize, this is not going to be easy.
In fairness, there are a few things on his list which I'd say actually rate as "potentially overpowered." Tasha's is a very strong choice as a first level spell. Psionics can be overpowered.
Of course, he doesn't seem to have any idea why psionics can be overpowered. No mention of nova capability, and how that can be disproportionately powerful if you can control your number of encounters per day; instead, it's "OMG a 1d10 power at first level!!!1!!!!!"
It's things like that that make me a little suspicious, to be honest. I mean, if he'd just said "Psionics is overpowered!" that would be one thing. But to say it and then single out something as utterly-trivial as a 1d10 damage power, or 2/- damage reduction? That sounds a little fishy. To single out Ambush feats as overpowered, and ignore Staggering Strike...which comes from the same book and is vastly better at locking down opponents?
Again, fishy.