I rolled a damage dealing spec character on game launch, and had very little issue finding groups for pretty much all heroic missions on planets over the course of 3 weeks of levelling. But now that the population has died off somewhat, it's near impossible to find groups for Heroic missions, even so on either of my tank and healer alts which I find surprising, as it's apparent it's not a shortage of roles. I have left Balmorra with 6 Heroic missions in log (stayed around for Bonus series too), and Nar Shaddaa with 4.
If Bioware don't plan on doing server merges, should Heroic +4 missions on planets be downtuned to Heroic +2 difficulty, and perhaps a few of the existing Heroic +2 missions downtuned to solo?
In my opinion no, it just dumbs the game down, when looking for a group I persevere until I manage to find people which usually requires no more than 10-15 minutes of searching and i'm not on a server with a huge population.