I've changed what I think when I hear someone has run 12 marathons and I'm worried I might be elitist

Agree with you. They'd get a pass if they were someone interested in running who doesn't run that much, or has never run a marathon but is elitist. But a runner with that time pissing on others — nah.

It's impressive in that <0.25% of people run one. 1 in 400 is reasonably impressive for such a universal activity. If, for you, someone needs to be 1 in 1,000 or 1 in 10,000 or 1 in 100,000 to impress you, that might fit in with a universal definition of elitist. BTW I don't think there is anything wrong with having some elitism about an area of expertise, but at least recognize it for what it is.

It sounds like you've undergone a shift in perspective regarding marathon running and performance over time, which is completely normal as you gain more experience and knowledge in the sport. It's natural to become more focused on personal achievements and improvements as you become more involved in any activity.

What you consider 'impressive' or a 'feat' is of no importance to anyone else, but most recreational runners are way less concerned with those things than people on this site seem to think they are.

They saw an event, and thought "hey, that looks cool! I like running marathons," and people congratulated them on their race. That's it. Everybody's just having a nice time.

I can’t speak for you, but are you sure the answer is “at least 6” and not like 40? Let’s just take 26, one every 2 weeks: if you routinely do 30k+ long runs as marathon training, don’t you think you could slow down and jog 42.2k every other weekend? It seems like a reasonably injury-resistant 2:50 marathoner could run a lot of 3:30 marathons in a year.

I heard a non-athletic musician talk how he finished NYC marathon in 5:23.

A 40-year finishing in 5:23. What an accomplishment !

Here's an example of my applying this to myself:

I was playing a game of never have I ever where the person in the middle says something they've never done and if you've done it you stand up and try to find a seat and the one person that doesn't goes to the middle. Kind of dumb, but you'll see where I'm going with this.

One guy in the middle says "never have I ever run a marathon". I was the only one to stand for that and I legit got an applause. I felt very stupid to get an applause for something that isn't much of an accomplishment. I could have said "never have I ever run a sub 15:30 5k", and one and only one guy would have stood up, but I'm not sure he would have gotten an applause, and his accomplishment is objectively much harder to achieve than mine.

So I don't just apply it to other people running a bunch of marathons with poor times, me getting an applause for that also felt really dumb, because it was for something that anyone in that room could have done but just wasn't choosing to do, for many reasons, only one of which is laziness.

Yes. They have done what you have done over multiple years and multiple training cycles. So yes, a person who has run twelve 3:51 marathons is a better runner than someone who has done it twice.

p.s. Your time, no offense, is so slow that you really should not be thinking along these lines. If you were a 2:51 marathoner and a guy with a 3:51 PR was bragging about doing twelve marathons, then you could be annoyed.

2:51 is better than 3:51.

12x 3:51 is also better than 2x 3:51.