To be honest after giving it some thought I don't care that much that an alternative for getting stronger weapons exists. There are 2 aspects to consider: usefulness and bragging rights.
When it comes to usefulness the user is as important as the weapon, if not more. Actually the difference in contribution when jumping from the previous weapon to a slightly better one can be marginal in comparison to player skill and knowledge and the method of acquisition can reflect that. You may have encountered people using PotD weapons and they may not have done that good, not because of weapon strength (which is fairly decent, especially for more casual content like dungeons or even NM raids) but because they got their best weapon grinding many hours in a joke of a dungeon that doesn't really represent the rest of the game so they may be still clueless about many things.
Also if you're not running difficult content to put a better weapon to use... that content can be cleared fairly easily unless you're super undergeared and/or super clueless (and even then you can get carried), so having better tools to play doesn't give you an "unfair advantage" regardless of how you got those tools. It's like who really cares.
Then there's the aspect of bragging rights or inspiring people. And this sorts on its own, getting stronger weapons by grindier means tells me different things than getting one by clearing difficult content. Grindier ones can tell me "oh, this guy sure has patience" or "sure is dedicated" or "he knew how to optimize the process" (or in the case of PotD weapons it can show a lack of actual knowledge of the game) as opposed to "this guy is good". Of course it's not all black and white, raiders may work on their anima while still on prog or while waiting to have good luck on their drops, so you don't take only the weapon into account but also the rest of their gear, which can reflect where they stand in terms of raiding. The new options to upgrading tome gear in 3.5 may make it harder to discern, but at least you can tell who's raiding and who just runs their roulettes (and there are other ways to see who is who on the raiding scene...).
(And yes, there's also the glamour factor but that kinda falls onto the bragging rights).
So the TL;DR is... having a stronger weapon BY ITSELF means nothing without the context of what that player is doing in the game.