Yes, Roger should have just broken off and made it on his own. It's obviously 95% Roger and that's being generous to the other members. I'm reading a Pink Floyd bio at the moment (Pigs might Fly) and Roger pretty much takes over the band after Syd's exit and his control freak, ego driven ways just got progressively worse to eventually culminate in The Final Cut. Don't get me wrong, I love Roger's stuff and in his defence the other band members pretty much let him take control as he was the overarching creative force and great at coming up with the concepts for each album.
Back in the earlier days of Roger, Dave and Richard "collaborating" (meaning Dave and Richard actually spoke up every now and then and added their talent to the mix) some of the greatest rock music of all time was produced. Dark Side of the Moon remains, for me, the greatest album of all time, with Wish You Were Here and Meddle (largely due to Echoes) close seconds. Nick Mason was the diplomat and along for the ride. He pretty much agrees and is quoted as saying "I was waiting for the drum police to arrive and say 'OK Mason, come along quietly'"
Animals was the first real sign that Roger was overly dominating the song writing, The Wall confirms this and The Final Cut is the nail in the coffin for any further collaboration.
Sadly, I believe Pink Floyd without Roger is lack lustre and visa versa.
I think when Roger dominated the songwriting but still let his bandmates have some input was when the band was at its best. Animals and The Wall are their two best imo. I don't think Roger will ever admit it but he was at his best when David would push him. I don't think Dogs would've turned out the way it did without David for example. Roger and David needed eachother. A Momentary Lapse of Reason and Radio KAOS are not exactly up to either of their standards. Amused to Death and The Division Bell are both amazing though. So there are exceptions.