Hrm...I dunno how I feel about this one.
Copyright aside - it's a horrifically stupid system in the US especially - this is something I'm not necessarily crazy about. RP2 had a LOT of issues, but the state of modding at the time meant that it got a free pass. We've moved to an era where people understand server performance, and modders - some far more than others - try and make their mods performance friendly.
RP2 is a bit like a '67 Mustang. Yeah, I have a modern one (2012), but I'd love to have a classic one in my garage as well. But when it comes down to it, it's the art aspect that people love. It's sexy, and there's a nostalgia. The horrible fuel economy, lack of any modern features (ABS, safety, trac control, countless engine improvements), and relatively low power compared to the new one are going to be painfully apparent once I actually own one, but I sure do love the thought of it. And every now and then, it'd be fun to drive. But the new one is gonna be a lot better in the quarter mile.
EDIT: To be fair, RP2 was a Mustang in an era where IC2 was a Steamroller and Buildcraft was a boat. So take that for what you will.