I don't know if I agree with this. My ex and I diverged about politics over a long period of time and though it wasn't ultimately what ended our marriage, it contributed to it. When I started talking to my current boyfriend, one of the first things I got out of the way was feeling him out on what his politics were and what his views on different social issues were. I wasn't going to sign up for another situation like I had with my ex again where in the end we disagreed on almost everything in those spaces. It is exhausting.
I guess it depends on how important these things are to you ultimately personally. If you think you will be fine with someone diametrically opposed to what you believe, then I wouldn't mention it either. But if they are important, you don't have to mention it on your profile, but better ask those questions very early on.