They should, because there are many things that we don't have sufficient evidence to prove or disprove, and sometimes it's useful to hold an opinion on them any

They should, because there are many things that we don't have sufficient evidence to prove or disprove, and sometimes it's useful to hold an opinion on them anyway. If a person can make the unsupported claim that gender differences do not stem from biologically hardwired tendencies, then a person should be able the unsupported claim that gender differences do stem from biologically hardwired tendencies. Also, not being able to make "unsupported" claims is a vicious cycle. If you can't say X, then any academic study is going to phrase their conclusions very careful regarding X (or possible selectively publish - I've seen this). And then X is going to be "unsupported".