In the beginning there were sticks banged on things and voices raised to the sky. It was the earliest music, and it was full of passion and primitive technique.[1. Note that I have no idea what I'm talking about since I'm not a music historian. Just run with the metaphor for the sake of grasping the argument. The exact history of music isn't relevant to the parallel I draw.] I have no doubt that Mozart and Metallica represent vast improvements in musical technique, but it's worth noting that neither drumming nor simple vocal music have been displaced by more "advanced" forms of music.
Roleplaying games are kind of like music in that way. There are a lot (and I mean a lot) of people who see later editions of (A)D&D as natural evolutions of the earlier editions, and then make the logical leap that the "more evolved" version is inherently better. Certainly, the state of the art has advanced and later editions have taken advantage of mechanical innovations that have proved to be good. However, if the incorporation of new techniques was all it took to make a new thing that is better in every way than an older thing, nobody today would listen to jazz given the existence of ska. In the case of music it's blindingly obvious that different genres have different æsthetic appeal regardless of how long ago they were invented.
So what is it that keeps roleplayers from recognising that older games have distinct styles and æsthetic appeals that many people appreciate? I suspect part of it is that the style of play can be, in part, disconnected from the rules system being used to evoke that style. Groups using D&D 4e can certainly use it to play political epics, and fans of AD&D 2nd Edition can use it for simple dungeon-crawling adventures that are little more than a string of tactics-heavy combat encounters. The stereotypical play style of any given system can be embodied using almost any other rules system. I think that this leads a lot of roleplayers to believe that using a more recent set of rules is nothing more significant than upgrading your computer's operating system—you can still play the same games as before, so clearly it is better to use the more advanced system.
To a point, this is true. If White Wolf's Storyteller system nicely supports the particular play style of your existing AD&D 1e campaign, but offers you even more system features that would suit your play style, it certainly makes sense to "upgrade" to Storyteller. I can imagine a group playing the sort of game where making that particular switch would be perfectly sensible, but would anyone argue that the play styles that original Storyteller and AD&D 1e were naturally suited to were identical on the strength of one single group's ability to fit their play style into both systems? Nobody being reasonable would make that argument. In the same way that blues and jazz are similar but distinctly different, so too different roleplaying systems can be similar but have their own distinct "naturally suited" feel and play style.
This thought was inspired by a comment on a Knights & Knaves forum post responding to common arguments against the existence of the old-school revival/renaissance:
You could ask a delta bluesman to start rapping, but wouldn't you rather hear the old guy play the blues?
I'm not really interested in debating the specifics of the original post, only in thinking about the statement that underlies the post and the quote above: The OSR is about continuing to enjoy a particular play style, not about rejecting system innovation outright. It so happens that those old games were "naturally suited" to that play style, and that many games that came later were better at a different sort of play style. But, like jazz and other styles of music continue to develop in parallel with the genres that have "evolved" from them, we can continue to develop new techniques and systems that are good for that old play style in parallel with system and play styles that have evolved from it. Imagine a world in which fans of jazz, baroque, or drum circles were scoffed at and belittled as being merely nostalgic. Crazy, right?
Besides, we all want roleplaying to endure as a hobby. If we insist that only the latest is the greatest, then we're dooming our hobby to be merely a perpetual fad with no meaningful continuity or staying power. Looking around I'm heartened to see that this just isn't happening. There is a lot of diversity, and a lot of people moving around between systems and play styles.
So keep playing and sharing what you like. Try unfamiliar play styles just as you would try listening to unfamiliar genres of music when friends share what they like. You might just discover something you never knew you were looking for, and maybe in the process you'll find that, like taste in music, there's no final reckoning for anyone's roleplaying style.