The other point, especially when players are not as familiar with a game, is that it's not always obvious to all players who has won a game at a given point. For games that are not fully scored until the end, I don't tend to sit and look at the board and calculate up everyone's final scores (this is part of why I enjoy playing on BGA, because I don't have to), and there have been plenty of times when my gut feel says that Player A will surely win, only to see Player B scrape a victory. Or to think I'm fully out of the game, only to find the margins were quite tight (and yes, I still lost, but not by as much as I thought). I like to see those things play out.
I also agree that when learning a game, it is useful to see what the decisions you made through the game led to - even beyond things like farmer placement in Carcassonne, but something like, did I stop building my engine at the right point and pivot to gaining victory points (in a game that has that kind of mechanic)? And honestly, I'm still "learning" a lot of games. I like to play a diverse range, I don't seek expert knowledge in anything really (at least, not the kind that comes by playing 1000 games of one thing and very little of anything else). But that's my subjective opinion.
I don't think a Person can reasonably expect their opponent to concede or not concede based on that Person's own opinion on the matter. I don't like it when people concede (mostly) but if my reasons for that don't resonate with someone else and they want to concede? Well, ok. In some cases, I might red thumb that person because clearly our play styles are not compatible. But I do accept that there's a wide range of opinions out there about when conceding is appropriate, and mine is not the one true way. Much like opinions on greetings, good game wishes, chatting, etc. Many perspectives. If they're not insulting you directly, they're probably not meaning offense, they're probably just doing their own thing.