So of course keysigning parties are one of those excitingly nerdy "I like to stare at scrolling green text in dark rooms" things. You're right that the main thing that actually matters is that "Linus" is still "Linus". Whether or not it's actually Linus Torvalds with passport number X doesn't really matter if we've all been trusting that signed identity for years.
FWIW, I have always independently signed anything I put on kernel.org, even in the face of a number of hostile emails (not from kernel.org - we always have the best relations) over the years from folks suggesting I was doing it wrong. Now the egg is on their face. If you want to release something, sign it yourself. Don't let some resigning service do it for you :)