I honestly don't think that matters that much. Yes it sucked to be the developer of a profitable Twitter client, but from Twitters point of view, those clients where potentially in the way of profit. Unless Twitter charged the third party clients for access to their API, how where they suppose to help Twitter make money? Increased user based? If Twitter can't make money on the users they have now, getting more won't help them.
So many people claim that love Twitter, it's their only source news, the way they keep in contact and so on. Fine, pay Twitter $20 per year, that seem reasonable, and it would keep spammers and trolls of Twitter.