I agree about the variety, in fact I welcome it. The problem, like I said, is that some DC mechanics are lousy to say the least, while others are insanely OP. And, personally at least, most of the time I end up getting the lousy ones and have to reroll several times until I hit the good ones. And then when you put the OP ones in a GL squad, it just sucks away the fun every time you have to face that squad in GAC or TWs. GLs are already top tier, they don't need any additional boosts, at least not anything resembling the current Padme cron, the now expired Holdo DC, Boushh's "death by a thousand TDs", etc. If they limit DCs so that only the stats, or at most the lv3 mechanics, are applied in a GL team, it would be a lot more enjoyable. It would still create a bit of variety, without severly limiting the players in terms of counters.
Not to mention how some DCs don't even work properly. A good example, for me at least, is the lv6 Inquisitor bonus, the one with the constant assists. It says that Inquisitors call A random ally to assist, yet most if not every time I go up against that DC, the enemy practically mass swarms each time they use an ability. I don't even know how many times I've lost a battle because of that, or some other, bugged DC.
Again, I have nothing against DCs. I especially enjoyed the Sidious cron, and am loving Wampa right now. I forget a lot of them once they expire, but when it comes to boosting less used toons or even turning good teams to awesome ones, I am all for it. It's when they also massively boost GLs that I have issues.