A. It's still not clear exactly what the issues were. Having use the app, I can't think of where Twidroyd steps on those toes. (I suspect that in its case Twitter is throwing a fit about trademark).
B. Suddenly cutting off two apps that are among the most popular on their platforms without prior warning is crappy for users. Publicly issue a drop dead date to fix the problems to the developers, and give your users a chance to be ready for things first.
I'm not arguing that it isn't crappy for users. I'm saying, if the vendor was warned about this and played games about it instead, they're the ones who did something crappy to the users.
I'm saying that there's blame to go around. If there's some sort of major privacy issue that has a direct negative impact on users, sure, I can see cutting it off.
Barring that, killing apps that are as popular as UberTwitter and Twidroyd with no prior public warning simply isn't the best way Twitter could have handled this.
B. Suddenly cutting off two apps that are among the most popular on their platforms without prior warning is crappy for users. Publicly issue a drop dead date to fix the problems to the developers, and give your users a chance to be ready for things first.