Funnily enough I wonder if they would have gotten more flack if they had just auctioned off the 100,000 licenses and see what the market would handle? I suspect they may have gotten more than $20 each and there would be less complaining as it's a totally transparent process.
Tweetbot is currently 2nd in the Top Paid and Top Grossing store charts, behind only OSX Mountain Lion. Those $1.4m will be in the bank in a few days. People didn't balk at the price one bit; I thought about it for a few minutes, and then went f#ck it, it's the only program good enough to make me tolerate Twitter, and devs gotta eat. I suspect for some power user, $50 or even $100 would have been fair game.