Eh, Iokath and Oricon are 2 different cases.
I agree that Iokath should have had an option like Yavin 4 (Ops or x8 missions), but Oricon really misses the mark if you don't make it an Operation. The thing is that the Dread Masters were tied to every Operation in SWTOR.
The bombing run to free them freed Soa (EV), they drove Karagga insane (KP), they corrupted Kephess (EC), they opened the door to Cthulu (TFB), it was one of them at the end of (SV), and DF/DP are their climax.
The Dread Masters are still my favourite storyline in SWTOR. And to some extent the game really did peak with DP.
But I 100% agree about Iokath.
Also, I just finished soloing the Dantooine heroics. It's tough, but you can do it so there's no reason to claim Dantooine is impossible solo.