I don't necessarily mean it's... purely cynicism but rather, what I've noticed, is a lot of games that gave me that wow factor when I was younger did it with stuff other than gameplay. I thought the combo's in CT looked cool as hell. FFVI's soundtrack was, and still is, amazing, and made me really FEEL something. But that was an aesthetic touch, and not something with the gameplay itself.
When I say that games haven't changed much, I mean they're still employing the same tricks they used to to garner emotional attachment. People remember Aeris' death cause it was the first time a lot of people saw that in a game, even though it really wasn't executed that well. Who's going to care when the dog in the new CoD game inevitably gets blown up in some equally poorly-executed manner?
No one, because we've already SEEN that trick, thank you.
Likewise, when you're less experienced with games, you're probably going to be more willing to overlook gameplay faults if the game... exudes enough of an aura to pull you in anyway. I'll use Panzer Dragoon Saga as an example here. Very well regarded game -- people love it. I personally think the battle system kind of sucks a lot, but it LOOKS cool, and if you're not really THAT experienced with JRPGs, the complete lack of difficulty or apparent usefulness of the special attacks isn't going to be as obvious.
As another example, I didn't really care about balanced before playing SMT: N. After playing SMT: N, though, every useless status attack spell, every non-threatening battle that I can just coast through without paying attention, all the pointless features really stick out to me.
The first time I played Legend of Mana, I was really impressed how in-depth the armor crafting system was. It wasn't until later that I really though about how there's no point in every crafting stuff in that game because the combat is irrelevant.
So I guess there's two parts to this:
1) If you play a game that wows you and it's legitimately good, there's a good chance you'll start regarding games differently -- effectively, it'll raise your standards.
2) If you play a game that wows you because of some aesthetic property or primacy effect, but the actual execution or underlying gameplay may be lacking, the next time you encounter a game that would, otherwise, be identical, you'll be less effected because you've already been exposed to whatever the trick is.
Although I guess you can also get unrealistic expectations. Ultima 4-6 were definitely NOT the standard when they came out, for instance,
(Also the metaplot in Chrono Trigger and Cross was ABOUT nostalgia, so I sort of love how people have strong nostalgic ties to CT).