It's a grammar thing. "Todo" is an adjective and can't be the direct object by itself. Direct objects must be a noun or pronoun. It's like saying, "I want intelligent," or "I want pretty." It sounds awkward, and while some people might say it that way as a shortened reply, there's actually an implied direct object in such sentences. Example: I want spicy [food].
Similarly, "Quiero todo" would be "I want all." To be grammatically correct, you should include the direct object: "Lo quiero todo" (I want it all).
For objects, they use "encantar" for love. "Querer" and "amar" are for people. For the differences, see this: