I'd hesitate to say that it's the majority though. Reddit tends to select for those that would spend a great deal of time on the internet, and a thread that would be about asking the issues with modern dating would probably select for those that have had issues with said dating that are frustrated enough to talk about it. Survivorship bias is very much so an issue in a discussion thread like that.

Reddit is not a cross-section of the population.

Reddit caters to people who are bored, angry, and have a lot of free time. People don't spend hours complaining on Reddit when everything else is going great in their lives. The people commenting in that thread (before it hit the front page) had to actively seek out that topic and choose to subscribe to it. It's the opposite of random sampling.

Reddit's front page is only an indicator of what active Redditors are thinking and saying, nothing more.

Folks forget just how big the Internet is. Thousands of people is very far from a meaningfully representative group in nearly any national context, especially so in the US. And globally? Forget about it, thousands of people is just so small.

I think thousands are still in the minority. And even among those you'll have some that give up on giving up.

Well, isn't that basically reddit: insecure young men?

Interesting, do you have link to that thread maybe?