Yes, it may be good for its time. But then you notice today that the game was pretty dreadful. The graphics,controls,gameplay. The Dreamcast could do better then that. (SA2 showed much of an improvement)
I am sorry, but why do you not understand the concept of aging? The whole reason we as a species have been able to improve is because we learn and improve on things and are able to get eachother better tools. Concepts, genres and hardware are improved with time when it comes to games all the same. Just because the game was not fun to you in like, what? 2005? Does not mean it should be considered shit, you have to appreciate it for the time it came out. I mean, are you one of those people who say all black and white movies suck because you were born later or some nonsense?
Sonic Adventure 2 obviously showed an improvement on a lot of things because the team was working on the platform for years then and were able to push it much much further, obviously. Next are you going to be surprised that big houses take more time to build then small houses?
A lot of us actually do like Sonic Adventure 2 more. I loved a lot of stuff it did more, like how it took a higher consideration of your score than ever in the series, stuff like that. However, to just say it is plain better in every way is just an opinion. It has a lot of issues, the first game never had a level as bad as Mad Space, how your jumps would "End" before you hit the ground so sometimes you would get hurt accidentally, how rolling is even more useless and not even possible by most of the characters or how when there were far less loops and they "Pulled" you through them, something which was not fixed until the HD version of Unleashed, not that it matters now anymore because you can boost!
Anyways, I am not sure you can understand most of this because you do not really know what you are talking about. Do you realize Sonic Adventure (and Soul Calibur, as a matter of fact) had much better graphics in 1998 than every single PlayStation 2 game until Jak and Daxter, which was released in in 2001? And even that is really close. That is a
three year difference! That is completely unheard of in today's games. Have some respect dammit!