I play on JC too, and I think there is a two-fold problem on the server.
Some teams will not queue unless they have their select premade, maybe with a substitution or two. Other teams will grab whoever or a few PUGs and just play. Once the teams that only play in when optimized start to queue the other teams really don't do well against them The teams not doing well begin having people not want to queue until the right people log in to optimize their group rather than feed the other team points The other team stops getting games and goes off to do other things The team that lost finally optimizes but now the group they were hoping to fight is gone The new optimized group fights a PUG of some sort or a lower ranked team Return to #3 and the cycle repeats
I can think of two guilds off the top of my head that did not even have a WZ ranking last night because they had not played 10 games. These are strong teams that should have a high rating, but they seem to only queue with optimized groups and as a result have very few games.
My PUGs will normally keep playing against strong/optimized, but other times that is not an option (a healer or tank leaves and cannot be replaced...DPS seems easier, usually). Two really good teams my PUG has not beaten are Uncensored and Imperial Blood Guard. Yesterday, we played all day and did not see either guild until about 9 or 10pm EST. We fought and lost to Uncensored twice (I think) and had no real chance. We then had a game or two against another guild (The Turks), which were great fight between two groups that had not optimized. We then called it a night because it was late and we had three people leaving.
As an example of unoptimized, we have had groups with a Commando, Guardian, Operative, and Sage as our DPS with a Commando and Sage as healer and a Guardian (full defense) and undergeared Vanguard (full shield) as tanks. We still managed to have a winning record for the night; but other PUGs with less geared Assault Vanguards, Shadow Tanks, and Sentinels have played the same teams and done significantly better on other nights. I have not queued with the same group for more than one night since rated has been released (I do normally have four people that come from a pool of six with the other spots being filled by whoever is available).
I still get in at least 8 games a night and normally more like 10-15, normally starting at about 6:30pm EST.