I've pugged HM Ops before and the only time they were not a major heartache was when the majority of the group were friends / guildies in vent and we only pugged a few missing dps or healer spots.
Every time I've tried a HM Ops with pug tanks, it was a disaster.
If HM Ops were added to the group finder, an epic level of complaints would appear, overwhelming this board about problems completing these ops. Then eventually, Bioware would end up nerfing HM Ops mechanics so that more pugs were capable of finishing it.
I did like the idea of locking the T2 ops and unlocking it when players finish the first ones. I'm less convinced this would actually work, based on some recent pug experiences.
If you're trying to do progression raiding, and you don't want to get in a guild, you should friend people that you've met pugging HM FPs and then invite them for HM Ops runs.
Which comes back to my idea of including it in group finder but locking it to progression.
Look at diablo 3 for example, anyone can play inferno by purely pugging whether you can beat inferno by pugging is another thing but everyone has a chance of getting there and beating it if they and their group are good enough. If you fail it's not the end of the world as you can go back and try with someone else another time.
The problem with swtor it doesn't give you that choice, as soon as you hit HM ops level and want to up your columi to rakata gear you have to manually find a group which I find in most cases isn't suited for pugging because as soon as someone rage quits unless someone can find a friend or guildie then the whole group is pretty much screwed, and there's also the option of joining a guild which a lot of people haven't got time to dedicate to and just want to try the content without hassle. Forming your own ops groups should be mainly reserved for friends or guilds to group up (i.e. people who are most likely to meet up again if they can't beat it that time) while randoms should be able to press a button to find a group full of like-minds on the same lockout and tier of op.
Forcing people to make private ops groups just to pug a HM op sounds a bit ironic in my eyes. Puggers need a random button for all content (with ops tier and lockout progression) while manual grouping needs to be saved for people likely to meet again.