Getting all the gear from naxx is a literal afterthought for most people I think. When you rationalize it out. Outside of the prestige from raiding naxx40 successfully there is nothing left of the game in terms of non social game play.
Think about it, after Naxx40 is done is there any real point to progressing? You have completed all content, there’s literally nothing left to accomplish. Can we do it again? Sure we can go through Naxx40 and all again but we know there will be a gear reset in the future so there is ‘no point’.
Stomp noobs? yes tons of fun for the raider and absolute hot garbage for the casual, getting 2 shot is not fun unless you can also 2 shot or at least have your skill allow you to overcome said gear differences. Unfortunately eventually gear > skill in an MMO.
Your complaint about a reset to zero type thing then is literally followed up by saying you are waiting for TBC to launch… isn’t that exactly the same thing? You level up again and go back to zero when you start raiding again. Outside of fringe gear, everything is replaced after the first raid in TBC.