As I said, I can't recall vehicular cyclists claiming that vehicular cycling will increase the number of cyclists. So don't judge them on that. I think increasing the number of cyclists is important, however.
Also, I don't know any place where vehicular cycling is particularly common. It seems to be enthusiastically practiced by a relatively small group of people. As I said, though, those people are the safest cyclists I know. There's no evidence that their practices are detrimental to safety best I can tell. Their practices might seem counterintuitive, but they have good reasons for what they do.
> Admittedly, to me it seems obvious that cars being separate from bikes will be safer for people on bikes than sharing the space. Just like how everyone would uncritically accept that walking on sidewalks is safer than walking in car lanes, because it just seems really obvious.
Again, what seems obvious is not necessarily true. I recommend that you look at websites like this one: http://bicyclesafe.com/
The author of that site seems to be neither in favor of pure vehicular cycling or infrastructure, though I think he's more in favor of infrastructure than I am. You can look through the most common types of crashes and see that most infrastructure does little to nothing to address those problems. And dooring, for example, is unavoidable in some infrastructure.
The infrastructure approach seems to implicitly assume that most crashes (or perhaps the most severe crashes) are due to cars rear-ending cyclists, but that's not true. The vast majority are at intersections. A lot of infrastructure I've seen amplifies the intersection risk by, for example, making cyclists less visible by placing parked cars between the main traffic lane and the bike lane. Those arrangements absolutely increase the number of conflicts at intersections. Yet people keep promoting this sort of infrastructure. (Yes, infrastructure done well can help. See other comments in this thread for more information on that.)
> you're looking at it as a personal style
No, I'm interested in my personal safety and also public policy. I'm not opposed to all bike infrastructure, just bad infrastructure, which is the vast majority of what I've seen. Given the choice between no infrastructure, bad infrastructure, and good infrastructure, my choice is good infrastructure. Most people can't tell the difference between good and bad infrastructure.
Edit: I can see from your other posts that you live in Germany. The infrastructure you see is probably biased towards good. I live in the southern US, and the infrastructure I see (if it exists) is biased towards bad. Keep this in mind.