I mostly just think it's a useful tool. I'm somewhat beyond it now, because you're tier lists generally become less useful when you know a lot about the overall gaming system, but, especially starting out, the notion of grading classes in terms of their ability to contribute to things, in a way that balances out power and versatility while eschewing more easy to come by tests of power, really informed the way I understood and approached the game. Also important to my understanding was the notion that game balance isn't about character versus world, but about character versus character. Imbalance in D&D is not a thing in a vacuum, with a wizard and a monk being equally balanced given parties that match their power, and the tier system is where I first learned that. And, while you can speak of newer and more robust, accurate, and flexible tier systems in the here and now (your tier system mostly hits the second of those criteria, but misses the first and third, I think), those systems owe a debt to the first one to come out, as they're largely patterned after the original and use it as a baseline of understanding. Moreover, I find it helpful in terms of the way it adds to our shared language within the game. I've found that "Tier three", for example, has a lot of conveyance to it. If the system doesn't seem to have that much value now, it's because we're so far removed from it that the things there just seem obvious and understood.
So, yes, I do reply to posts on this topic, because I think the system, on these bases and others, is one worth defending. If you honestly consider this sort of discussion an infection, then it'd likely behoove you to stop contributing to that infection, because you and faeryn were the ones who actually started up this debate. It seems rather hypocritical to make a big deal about something that you're pushing towards with your own actions. And, again, I agree that the tier system is flawed. Many arguments in the past have been rather convincing as to the placement of individual classes, occasionally even with the requirement that you stay within that book limited setting (with the warlock and warblade as two that seem plausibly misplaced). But, for its imperfections, the tier system also has a lot that it's right about, both the general placement (rather than precise and specific placement) of classes, and the underlying philosophy.