including mine run alt runs to help gear others members who don't get the opportunity to raid as often through HM content on the weekends.
Look at the the "separate HM from NiM lockouts" thread on why that doesn't apply to most guilds. Not only that a lot of guilds only to the hard mode content on Tuesdays, Wednesdays and Thursdays meaning those who only have weekends free due to work and such are stuck with story mode runs anyway.
PuG runs can be just as capable as long as they are as organized as a guild run would be (everything planned, TS etc). The problem with the majority of PuG runs though is the general recruitment and planning sucks for example when people just spam for the first tanks or healers they can find, don't bother checking gear, no TS or vent meaning you end up with a group that's as organised as an EA board of directors meeting.
What would help the PuG scene is instead of people spamming chat and forming groups on the fly, maybe if more people planned out these runs in their server forums in advance or if there was some PuG lfg site that people can provide more info than we currently can in chat.
I feel the status quo at the moment is though is guilds love the fact there's no platform where PuG's can organize themselves bar general chat as every wipe or failed group increases the chance of them asking to join a guild.