As I've mentioned before I'm not totally against PUGging raids. I find its actually an excellent way to get to know people on the server and sometimes a handy recruiting tool. Depending on your guild rules, there are some raids to PUG and some raids to save your lockout for your guild.
I had a guildie today all distraught because he was saved to Naxx 10 helping a guildie out. He apologized profusely when someone was putting together a "Badge Run Blitz" but couldn't heal it. At this point Naxx 10 is like running an extended heroic with more gold and shards. We've progressed beyond it, so lockouts are fair game.
I get a wee bit crabbier when folks get locked out of our current progression. We're actually still working on Ulduar 10, and need to draw upon any available resources to move forward. Guildies can feel free to run Naxx, Vault, and Obsidian Sanctum to their heart's content. Usually when someone asks for my blessing to run with another group, I give it if they have to miss guild times or we're unable to get into the group.