Simple answer is, many rappers shit on wayne.

this is true wen they were more underground they were pretty dope.

about that whole thing that Tech is going mainstream here's what i think :

if you listen to his verses it actually sound like every other stuff he has done before, it's not because he feats big mainstream figures that he is.
listen to this and you see :
Tech dropping the same old sick flow and stuff
Wayne dropping the same old shit rap and stuff
T-Pain dropping the same old auto-tune

Tech stayed true to his self... and "big" rappers want to do songs with him!

This is so funny. The only old stuff you mentioned is Anghellic.
Sorry but 5 years isn't old.

Tech isn't doing mainstream either.
He does his same shit as he always did. And that shit is... OMG! Whatever the fuck he wanted.
He can work with whoever he wants and he'll still be same tech. Doing what the fuck he wants.