Yeah I agree, this concept is not restricting anyone who desires to have a small 'tight-knit' clan, you can still achieve this with a limitless clan cap by simply not inviting further members to join.
I can't speak for every other aspiring large clan, but with over 250 members so far, I feel I can approach, join and build a rapport with each and every member I happen to run into or group with due to social community dynamics set by our team of admins.
Its with any MMO, some large guilds/clans can feel diluted and having you feeling that you're just a number and not part of a team, then other large guilds make you feel like you're part one big social network, rich in support, positivity and team-play resources.
If being part of a smaller clan to gain that sense of closeness is your thing, then do so, no one has or ever will stop you. Since when has it become an issue to people on how other people choose to affiliate themselves socially in a game? It's not like a clan vs clan pvp imbalance issue.