I'll speak from my personal experience.  I just don't instance much unless I have a bunch of quests while leveling.  I know very little about the pre-70 instances.  Temblor only ran I think 3 total instance runs on the way to 70 and one of those was Durnholde COT.  

We have a lot of players who have given a lot of time helping people on runs guildies needed, when the players who decided to go had NOTHING they could possibly want from the run, even after rep was meaningless having hit exalted with the faction.  For me, the well of generosity can feel kind of dry sometimes and if I'm gonig to spend 3 hours doing something I'd like to have it be beneficial once and a while for me  (selfish? PRobably, but being honest here).

We have a lot of people listed when you look at the guild list, but of late the list of people online hasn't been too long.  Despite burnout and whatever else, I still think we have a lot of people who are willing to help in many cases.  You're not the only man in your raft though.  I still pug a lot and had to while leveling.  Unless you find someone who is quest-for-quest at the point you are it's hard to level with anyone.  We all do what we gotta do and if someone is around to quest with I see that as good luck.  We aren't a huge guild where just sheer numbers is going to always have someone willing and available to run a particular instance.  

I apologize if you think I've purposefully snubbed you but it wasn't my intent, maybe just my selfish attitude.