I should make this clear: i am not here to argue over my own group not wanting to do the bosses, i am here to argue the fact that every group i run into doesn't want to do these bosses, about 95% of groups i run into have people who just want to skip to rajh. I can get a guild group if i wanted too, but i don't want too -- i like playing solitary. There are people who need gear off these bosses and i doubt i'm the only one who has argued this in the past.
edit: fixed an error
Well, a preliminary thought: If you want your solution to be a good solution (whatever it may be), at least make sure people that DO want to skip to Rajh still have that opportunity.
So, I see your point, but I don't see how Blizzard could implement something to really handle what you're looking for (short of some genius UI dev taking on the case). Think of it this way: If there are 3 mandatory bosses in H HoO and 4 optional bosses, that means there are 2^4=16 combinations of bosses to be killed on a given run. That fact in hand consider the problem with ONE naive solution (just off the top of my head):
Say that Blizzard puts in a new option in the Dungeon Finder that lets you choose a preference for doing optional bosses or not. How would that be designed? If I ONLY want to do Ammunae for the int/spirit/crit ring, does that mean I have to select the "Yeah, I'll do the optional bosses" and be stuck in there for another 3 boss kills? And clearly there's no good way to select specifically which bosses you want to do (think how much 16 different options for H HoO would fragment the population queueing... queues would take forever).
So, that's my straightforward solution, and a straightforward reason why it doesn't work. Ultimately, I don't see a good way for Blizzard to do anything about this, aside from letting people handle it as they want themselves. After all, it only sort of matters that you're a "solitary" player, if you're participating in group content -- ESPECIALLY if you're not willing to go through the effort of finding a group that matches your mindset...
I think you're just putting too many constraints and demanding things go your way, when it's just plain unrealistic. I think a better approach would be to try modifying how you approach groups/5mans in general, see if you can find a way to get what you want within the current system.