I think you either missed or are glossing over Michael Sippey's blog post today where he said "in the coming weeks, we will be introducing stricter guidelines around how the Twitter API is used". People aren't upset about the old "stricter guidelines" you are quoting, they are upset about the new ones.
It was poor judgement and poor PR to lob that out there before they were ready to actually spell out what these new "stricter guidelines" are. It creates fear, uncertainty and doubt among Twitter API developers and they are getting sick of fear, uncertainty and doubt, its been going on for a long time now.
Twitter's message bus, API and identity system have become valuable Internet resources. But Twitter has never been particularly great at thinking of innovative uses for it or developing great clients. There are a lot of really interesting and different ways to use those, regrettably they are trying to kill most of them and inflict a homogonized, boring, monoculture on their user base they can monotize, which will make the experience progressively worse.
At this point I imagine most API developers are wishing there was a new message bus they could move to but its a daunting challenge to field one, even more daunting to get a critical mass of messages moved over to it to make it interesting, and really daunting to fund it without resorting to all the lameness Twitter is now knee deep in.