This.
It's becoming waaaay too similar to the endgame of World of Warcraft, or any MMORPG for that matter.
Other than taking yet another swipe at high level PCs, I don't see what this point contributes and is indeed besides the issue. The very premise of the issue raised is that loot that drops makes some particular enchanted gear un-competitive. If you want to gripe about high-powered loot, it seems counter-intuitive to me to undermine the option with the more serious cost (as XP is harder to earn than gold or loot at higher levels).
I also think it's a massive generalisation to talk of character retirement in this context. Speaking personally, my desire to retire PCs is driven less by whether they've hit that magic lvl 20 (none of them have) but more by how interesting and challenging they remain to play. The connection between enchanted gear competitiveness and character retirement is subjective at best.
This is not a swipe at high level PCs. My main character is becoming a high level himself, so I'd be a hypocrite to do so. I'll try to answer the best way I can without getting too off topic...
It is my personal belief that nobody should be forced on anything, especially PC retirement. If a player decides to play his character and stay out of trouble, he can live forever and that's fine. Another thing completely is to have systems in the game that -encourage- that. This system seems to be one of them. Because even if a character is stagnant and no longer has a story to tell, he can spend days and weeks (months?) just "farming" exp and hoarding these items. There is nothing wrong with that, there are millions of people who do that every day on other computer games... The question we should ask ourselves: "Is that what we want for POTM?".
Not even DMs and developers can force you on how to play, but they can make systems that encourage certain behaviors. For example: RP exp system is awesome because it encourages roleplay. The location exp system is great because it encourages higher levels to leave lower level areas. You can still decide not to roleplay, and you can still stay in Vallaki as a high level, nobody will stop you, but you are encouraged to roleplay with people and leave vallaki after a certain level, and that seems to be a good thing.
Enchanted items, while fun and flavorful, seem to discourage character retirement. And as Lucadia accurately stated, I do believe that character retirement is a good thing, especially when that character has become stagnant and no longer is telling a story.