I’m not sure it could work that way for a lot of the humanities though highame. It’s perfectly legitimate to write subjectively about non-scientific subjects like philosophy. (Its not legitimate to do shoddy social science research like you say, but that’s different from philosophy, ie thinking about ideas). It’s definitely not OK to effectively disallow and ostracise colleagues and students from having a plurality of subjective (legal and peaceful) views.
So universities could enforce the requirements around free speech better, defend their staff better, and they could require critical thinking to be taught for Arts subjects. Not just research skills. Honestly with the signatories of that letter I think it’s a symptom of what seems from the outside like quite a horrible academic culture for a lot of them. Of the UK ones various are junior, may not really have any particular awareness of these specific issues particularly but (I would bet) want their name going around on social media attached to virtuous-looking things alongside a few big name people making them all look like peers. It’s lazy but it comes from insecurity too.
I don’t know if academia was always this way but the low pay, job insecurity, the REF, the admin load, the hours, the requirement to be on social media, all seem to conspire against women (especially with kids) and to promote dickish signally behaviour like this ‘open letter’ ostracism tactic which has no solid foundation in actual academic argument.
Stock seems like a straw man here for most of the signatories- as they haven’t even got their objections straight. To me it looks more about self righteous, self serving careerism from junior people tilting at windmills by signing this thing. ‘Problematic views’ or insufficient commitment to the cause has always been a good way to clear out or mute the middle and upper tiers in any political hierarchy. It’s a dangerous culture to feed though because nobody is ever perfect enough when political goal posts can be moved all the time but must be stuck to. Academic work will always be political but it is also a discipline with an aim to continuously improve knowledge, it should not be just paid political advocacy with penalties for those who don’t adhere to the dogma.
That’s why its essential that academic culture needs to robustly maintain that debate is OK and is needed- debate has an essential purpose in maintaining academic rigour and freedom and defending the central purpose of gathering and sharing and testing out knowledge. #yesdebate