For context, I am fortunate to have been “FFB”.
“Ba’al Teshuva,” not unlike “Am ha’aretz,” has a very different meaning in the vernacular from what it means in the Torah.
Your anecdotal evidence is not compelling. I obviously don’t know the individual whose story you relate, but I do know numerous Ba’alei Teshuva who are happily married. Many of them married “FFB” spouses. I happen to know a good number of geirim who are married, and a fair portion of them are also married to FFB spouses.
I also know many people who are FFB who – unfortunately – never married.
The protagonist in your story likely has more than just the fact that he’s a Ba’al Teshuva to explain why he wasn’t able to get married.
In my experience, Ba’alei Teshuva are, by and large, fully accepted and integrated into the general Frum community. Sure there are FFB people who can’t get over their own immaturity. There are Ba’alei Teshuva like that as well.
Please don’t paint the entire Frum community with the black brush of hatred.