Can't tell you how many times I've been in a match and thought to myself "god, these guys are terrible for pubs" only to later realize it was imp v. imp.
Note that Ush can make this realization only belatedly while playing on the Frogdog team and capping grass first
Very recently there have been a few new looking Empire guilds running pre-50 premades and really thrashing the Republic good and proper.
I've noticed Notorious running lots of lowbie premades, but to place blame where it properly belongs: they're actually a mirror-guild of Infamous, a Pub PVP guild.
TLDR: Blame the Pubs.