He was like Data, but he didn't actually desire to be human. He just was, so is the nature of having human programmers who can't fathom something that does not in some way reflect themselves and their own nature. I personally think the Doctor is a good mix between Spock's clinical detachment, McCoy's bossy attitude towards patients, and Dr. House's acerbic, snarky wit. Crusher was boring. The Doctor is among my favorite Star Trek doctors along with McCoy and Phlox. Brilliant actors, the lot of them.
Also, one couldn't help but feel for the Doctor in the beginning of season 1 where people didn't give him basic courtesies. I mean, he doesn't ask for a please and thank you, he knows he's a hologram. It took Kes for him to realize he really was something like a person, not a thing.
*insert evil laugh*