^Exactly. As someone remarked earlier, Data definitely had emotions even if he didn't have specifically
human emotions. He may not have laughed or cried or thrown temper tantrums, but he definitely had aspirations and insecurities.
A thinking being can't
not have emotion, because emotion is simply motivation (both words come from the Latin for "to move"). A being that's capable of choice rather than simply acting on instinct or reflex must have some kind of incentive for favoring one choice over another, for preferring one outcome to another. Data (or rather, the show's writers) always defined emotion too narrowly by assuming that only human emotion counted.