I don't think that Data got the better part of the bargain. Data, in his own quirky way, is kind of cute.
I agree it seemed short sighted that Data's exploration into love and sex was strictly heterosexual. I'd think Data wouldn't have a human limited sexual orientation. I've theorized that Soong gave him this limit, to give Data his own heterosexual orientation. The man is kind of an egomaniac, and he made Data in his own image, so I can imagine he wanted Data, and Lore, to have the same orientation he had.
Now, on the subject of Spiner being interested in kissing another man...just remember, I didn't bring this up. I always had the impression that Spiner would be interested in kissing another man. Besides, they are actors. Doing love scenes aren't about the actor's sexual interests.
For what it's worth, Frakes wanted a male actor to play the role of his gender neutral lover but tptb insisted on casting a female. For their special metaphorical gay story.