If it's the vast majority, then that's close enough to be automatic. There are exceptions (like the rogue daggermaster), but they just prove the rule.I'll venture to say that the vast majority of fighters, barbarians, rangers, some rogues, probably eventually get a superior weapon etc. Its not automatic, its just a common feat.
It's not the best first feat, but by paragon level, any [W]-dealers should have made the upgrade.