One of the activists' pet peeves is also that there are viable alternatives for everything. Like MRI in humans for fields like neuroscience. Which is, at least partly, complete nonsense because of the lack of a decent temporal resolution. Yet this argument gets been repeated over and over again and as such believed in by many.

One thing though: as far as I know (from people having worked in the US, with primates), the IACUC rules for housing like cage volume etc are still not really sufficient.