"I don't know why someone can't believe in dinosaurs and also accept the possibility that there can be humanoid types of life forms that could have arisen from contexts that did not have dinosaurs."

I can accept the possibility there are humanoid life forms, it's just that the chances of it happening once are infinitesimally small, so the chances of it happening twice are even more remote. As for humanoids arising from contexts that did not have dinosaurs, that is utterly irrelevant, as the body plan for modern vertebrates was fixed long before anything with a backbone heaved itself onto the land for the first time.

I believe in dinosaurs because I go and dig them up, prepare and identify their bones myself. I know world-class palaeontologists who are on the cutting edge of discovery about these incredible animals. As I sit here typing this I am surrounded by solid evidence for the existence of dinosaurs.

I believe in UFOs because I saw one and the sighting was verified by the local airport, but I have no evidence one way or another as to what it was - I simply know it was there (of course, I have speculated for years to myself what it might have been).

I can see we're going to have some sort of alien aparthied in the future; if you don't have two arms, hands, eyes, ears and one mouth and nose you're not going to be considered 'humanoid' and somehow inferior. If you've got none of these attributes and eat rocks then you're right out of it - shades of the Horta here!