Vash did not go unnoticed, by fans, nor did her relationship with Picard. A surprising number of them found it to be ... inappropriate ... namely, in that he was too old for her. Personality mismatch was another reason. And there were others, to be sure. But, that's what we were presented with and whatever is onscreen is onscreen.
Fortunately, it's just vague enough, where it's subject to interpretation, so that both camps - those in favour of it and those against - could be satisfied. Personally, I would've loved for them to have had a gratuitous sex scene - but not in Gene Roddenberry's STAR TREK, thank you, very much! We weren't going to get that.
I loved it when Picard was sent back in time to "play as" himself in TAPESTRY. Patrick Stewart got to make out with that 20 year old chick, before commercial and I'll tell you something about that: I could've sworn I saw him slipping her the tongue. I know! I know ... but, tis what I saw! Patrick seemed to be enjoying himself, thoroughly and, what's more ... it fortified his resolve to be a Sugar Daddy, that's a fact!
Even now, he gets with younger women, but at 70, or whatever he is ... he's had to settle for his Gold Diggers, a little bit older. But never did he find another like Jennifer Hetrick. She was the coolest - and the hottest - of them all. Shatner ate his heart out, undoubtedly ...