I wonder if 25-50 years from now, film buffs will go back in time and watch Tarantino's films and think "WTF is this garbage?" Kind of like watching Fletch with Chevy Chase, not laughing at any point in time during the film, and then when the film is over you say "Well, I guess that is what was considered 'funny' back then."
I doubt it will age poorly though. Here is my reasoning:
If he fleshed characters out to the point of really caring for them and then used his gift of long tension-building dialogue, he would be considered an overall master at film-making imo.
But then it would create a different tone: the violence would almost certainly have to be less stylish because it would be far more emotionally demanding on the audience and this is kinda why I just accept him for who he is as a filmmaker and enjoy it.
He seems to thrive in the "guy flick" mentality of his films. But if anyone tries to put him up with Hitchcock, no way ...
Hitchcock usually had great characters in his suspense flicks: Jimmy Stewart in Vertigo, Marion Crane's personal crisis and dilemma under-girding the shock of her murder in Psycho ... what's the point of her struggle if Norman just kills her? To the world, none. To us the audience, everything. She had a mini-character arc going from willful illicit affair and theft to inner repentance and an unwitting victim of peeping after she is seeking redemption bringing a sense of sorrow to her unsettling killing.
If Tarantino made Psycho, he would start in the motel and only introduce some character catagories within witty banter (almost impossibly witty) and use dialogue devices to get to the murder. He almost never has a death come out of nowhere for the character but shows a conflict and all deaths arise from dialogue that ratchets the conflict up to blows and bullets.
He is really good at that though. But he is no Hitchcock who mastered several scenarios of suspense, not just one.
I think he will be seen as over-rated but not to the point of "WTF is this garbage". JMO