This can be quite a heated topic here on HBT (see
https://www.homebrewtalk.com/f13/aging-beer-facts-myths-discussion-84005/ ). Personally, I think people have mistaken the "new" evidence that it's not harmful to leave your beer on the yeast for an extended period for a mandate that you must do just that. Chances are that whatever your favorite commercial craft brew is, it spent less than 3 weeks in the fermenter. If they can do it, you can, too. Just mind your pitching rates and fementation temps and you can enjoy a great low- to mid-gravity ale in as little as 10 days if you force carbonate.
If you like to use a long primary I don't think that's a bad idea on its own, but the extent at which it's being advocated by some is getting ridiculous. I recently read one thread where a brewer was trying to track down a persistent off-flavor in several of his brews including a 1.065 ale that spent four months in primary / secondary. Several of the posters still insisted that it was just "green" and would age out. "The yeast will clean up their mess" is good, easy to follow advice for a new brewer, but eventually, it's probably best to learn how not to make the "mess" to begin with.