That's just a reflection of Valencia's time here, I think.
There's a lot we can say about Valencia. He worked hard, he made the most of his talent, and he clearly loved the club. But if we're brutally honest about him there's a lot else you can say too. He was not good enough to play in the position he was signed for, he was never a particularly great full back, and he had two good seasons at the club.
Now that his career has wound down and he hasn't been a fixture in the first team as much no one has actually missed him, or even noticed he's gone. He's just gone from meandering along being not quite bad enough to be replaced to being out of the side and out of mind.
I don't think he's a player that's anyones going to look back on with any great fondness. He was a good servant and did what was asked of him, he seems likeable, and criticising him seems a bit like kicking a puppy, but he's the sort of player that people in twenty years time will go 'oh, yeah, I remember Valencia, he was alright, wait, he was there how long? God, I barely remember that at all'. Those players don't tend to go out with a huge fanfare.