The problem was that SA was totally new. No one cared about glitches, they had eyes that were sparkling and couldn't live without their dreamcast.
Uhh no. What people considered buggy gameplay now was not even similar back then. Compare Sonic Adventure to some of the highest rated platformers of the time. Crash, Spyro and Banjo-Kazooie. Sonic Adventure has more features, more gameplay options, much bigger levels, much more music, more FMVs, a longer and more detailed story (not a very good one, but still), hugely superior graphics and was just overall a much larger experience than all of those games
combined. If you cannot see that this is a massive achievement for the time you need to GTFO! Especially when compared to something like Tomb Raider, Sonic Adventure just played a billion times better. Obviously games improved, but Sonic Adventure was an improvement from basically everything from the time.