I have heard of this and even seen it, but in general I would say it is way off base. It is a thought pattern held by people who wish to swing, just start swinging, or think about/read about/study swinging.
Most (Yes most, but not all) couples who swing develope very lasting relationships with certain partners. Couple who spend holidays together, weekends, camp, etc…. Friends with benifits they say.
Some couples require it, and some just fall into it. The fact is… you can't hang out with a couple weekend after weekend doing whatever it is you do plus have sex and not become close.

As for the homophobic part of swinging….. that is true, but not so much in the younger crowds.
The newer generation of swingers (under 35 set) doesn't seem to care so much. I have been to parties and bar takeovers that cater to that crowd mostly and I can say it is a very bisexual friendly situation for both men and women. Males openly dance, kiss, grind, etc.. with eachother.
The groups that cater to the middle aged and up lifestylers however are a bit put off by the behavior.
You could say the same of most vanilla bars however. Older groups are less able to have open minds.

Safe sex? No such thing, but I will say that swingers in general are more hygienic than the average person and most (not all) are sworn to condom usage.

My partner and I are "swingers" (I call us non-monogamous, but our version of non-monogamy fits the commonly used definition of swinging).

In the beginning of relationships, they're mostly monogamous. There's still that "can't-get-enough-of-each-other" phase, and we don't typically want anyone else. And that's okay.

However, in all relationships that I'm in, the prospect of possibly bringing other people into the bedroom in the future HAS to be at least on the table for discussion at some point. I know that I can't be monogamous to one person for the rest of my life. And in relationships that I try to be monogamous in, I end up cheating.

This is what works best for me, and for my partner. I enjoy watching my partner receive pleasure, even if it's not from me. The fact that I'm there eliminates all of the jealousy, and it's a joy to watch them enjoy themselves. I also find that it bonds us to each other very deeply, and the sex that we have afterwards is more intense and connected.

I think that more couples should explore options other than monogamy. I think it would lessen the divorce rate, and create happier relationships over all for many people.