Without that clause, many major researches will leave UC because they have virtually no journal to publish anymore. Indeed, that sucks, but you have to attack this problem in steps.
The fact that it's an opt out is significant. Most universities haven't even gotten as far as saying "dear staff, please think about doing that open access thing once in a while". UC says "You're going to do open access, unless you really don't want to and then you can do otherwise". The push is very strong. The university, centrally, very clearly and unambiguously declared what they think is the right direction. Scientists can respond by asking for UC's (financial / political) support with starting new initiatives and open journals, or when pressuring existing journals to go open.
In the longer term, actions like these may actually help UC attract top scientists. If you write a paper, you prefer it to be read by as many people as possible. The only reason to be OK with it being behind a paywall is if, somehow, through something culturally grown, it is the only way to advance your career. If you can have similar career chances publishing openly, then that is very attractive indeed. I think many researchers will find that this makes writing papers more worthwhile, more fun.
I'm looking forward to when all modern scientists have a blog on which they post abstracts and download links, including comment threads and all the fast, dynamic interaction that entails.
Why would they leave? Major researchers need to publish in major journals in order to get tenure - if they choose to publish only in lower quality open access journals, they are perceived as weird and low status.
If UC requires open access this problem is solved. Every researcher has the perfect excuse for why they didn't publish in a closed journal.
I dunno. As a CA taxpayer I agree with you. But as someone who understands how important it is for academics to publish in fancy journals I kinda understand. I'm torn on this one.
