Why do monkeys like banana's?
Because that's what's handy to them.
I think that monkeys like bananas because they are one of the main sources of food in their native habitat. I also think that they like anything that is sweet.
It's what is available to them.
Some gorilla's eat baby deer, but monkeys usually eat leaves or other fruits besides banana's and some time's even bugs.
Because they are sweet,
Because bananas are good....
Same reason you or anyone does.
Because monkeys live in banana trees.