First off there was an active pugging system pre BC, you just had to be on the right servers, i remember being part of a pugging consortium of players who achieved better raid clearing results then the top guilds.
Used our own private channel like a guild chat, but stayed in our respective guilds.
And if you left a guild based on on gear score, chances are you'd be rejected from the next guild for in experience and lack of gear, plus you'd have run out 1 guild out of a small list of guilds per servers clearing content.
Nah not really, as you just said yourself "you had to be on the right server" and you were in a "pugging consortium" which helped you. I was lucky enough to be in a very good guild on my main in which I played all content. I had a horde alt and I was lucky if I got into raids, not becuase of the elitist jerk attitude which permiates the game now but more because the content was difficult back then and it actually took organisation just to kill trash never mind the bosses. Pugging in instances only really became an option once the content was thoroughly nerfed and even then it was a chancey business at best.
To the OP;
WoW is never a hard game to pick up or a hard game to enjoy. I have a love hate realtionship with WoW, I love the game but I hate what the community has turned into.
Whilst it is the best game out there in regards to MMO's it has the nastiest, most mean spirited bunch of petty morons who only look after themselves as a community. This is of course a generalisation, get in a nice guild and you will generally have fun and be looked after, but the community as a whole is what I have said above.
No one wants to try, everyone wants everyone else to do things for them and they want their own game to be simple and painless at the expense of others. All they want are new shiny purple items and nothing else, the way some people carry on over this is sometimes quite disturbing.
Since my old guild disbanded at launch of WotLK (best of us left the game for the way it was changing) I have dabbled in PvE but that generally tends to be where the community is at its nastiest. Though I did have some good times with the newly formed ocuk guild on Kara, they are a nice bunch of lads.
I am back to playing PvP like I did at launch of the game and I am having fun again. People can still be funny but the PvP community (at least from my experience) tends to be more friendly, fun and accepting. Plus there seems to be some overdue TLC coming the way of PvP over the next few patches and expansion so all is good.
Personally OP I would say give the game a try! Its a great game and hopefully you will find the right people in there to enjoy it with. Good luck!