Why don't we just put the monkey in a zoo and feed whatever it wants. The Strawberries and Bananas we make fruit salad of and keep for ourselves ?

Clearly this question is metaphorical. The monkeys represent uninformed (unenlightened) people. The strawberries represent better ideas which are produced by higher, better informed understanding (higher consciousness). Bananas on the other hand represent less informed, lower or more primal thoughts which produce less desirable ideas. Of course,in this parable, you first have to accept that the greater the sweetness the more desirable the fruit. The Biblical equivalent of this parable would probably involve a mustard seed and planting instructions.

How is this determined? Do the monkeys press a button to indicate which one is sweeter? Or is it just assumed that the monkeys want the sweeter one? What if the monkeys are acting rationally and pick the food with more calories? Gram for gram, bananas have about four times the calories of strawberries.

But what if the monkeys prefer bananas precisely because they aren't as sweet? What then?

Actually, give them both, and I'll guarantee that there won't be any strawberries or bananas left.