Trans guy here - in part what I think might be meant is the pressure of expected romance. Like it is certainly a thing when younger AFAB people are trying to find regular old cis male companionship that there's often this sort of pressure where you can tell when someone is crushing on you and it's a matter of if and when they make their move. That time can be dreaded because a lot of the time once someone makes their move if the romantic advance isn't accepted the friendship disappears and the feeling left behind is that you were never a friend at all. That you were tricked into valuing a friendship that wasn't real because it was a down payment on an expected return of sexual or romantic affection.
And yes, I am aware it's awkward and hard to stay around someone who rejected you romantically. It's also hard to lose a friend because of something you had literally no control over and to mourn that. Sticking around and remaining a friend and getting past your romantic flop is a service to all sides involved if what you actually feel is cut off from friendship. Otherwise it really makes the assertion that this isn't about sex ring very hollow.
In my 20's an asexual closeted trans person who counted men as my tribe and wanted nothing but friends that felt normal and lasted - at one point I got so desperate I agreed to a sexless "romantic" relationship by way of fear of losing my best friend. Even though my "boyfriend" was a perfect gentleman during the time we were "together" I ended up in a two year long situationship that in the end felt skeezy and colors that time of my life in a sense of wrongness. I never developed romantic feelings and that whole set up ended up being sickening and oppressive. After it ended that friendship became remote and I lost what I valued somewhere along the line anyway.
It doesn't surprise me that so many women aren't all that empathetic to the male loneliness epidemic even though in this post it is being expressed in a really shit way. It doesn't take many guys dumping you on your ass simply because they got attracted to you and decided not to stick around afterwards before you start feeling like their lonely heart is not your problem to solve. It feels just like if you had a friend who was using you for your money or some sort of service you were providing. Feeling used and discarded is traumatic. People who get hurt this way start getting very suspicious of new friendships and maintain distance because they are guarding from getting hurt again.
In summary - It's really hard to relax around someone who is coming at you with an expectation you might not be able to meet. The more obvious it is the more you can potentially save yourself the trouble of not getting invested early.
Unsure what this has to do with my comment which was in reply to your statement about not knowing what the statement in the original post likely meant by "relaxing". I never stated the friends must be women.