Virtua Fighter's still got sequel from SEGA even after Yu Suzuki left. Shenmue wasn't that lucky.
I'm sure if Shenmue got a sequel from SEGA, Yu Suzuki wouldn't have to try to make it himself.
Most likely the higher ups already rejected all sequel attempts since the franchise weren't profiting in the past.
But they can't just drop Shenmue franchise for being not profitable enough, and then invite Ryu to Sega All-Star Racing like that! That's kind of unfair to Yu Suzuki.
Sega: "No, we won't produce Shenmue III for you despite the dedicated fanbase that had been waiting for the last 18 years. We simply believe that Shenmue is not a franchise that's worth our interest."
Suzuki: "Fine. I'll take Shenmue and make it myself given it's still my franchise."
Sega: "That's fine, we got Like A Dragon, which is like Shenmue, but it isn't. But we will still put Ryu in a Sega All-Star game because he is still regarded one of us."
Suzuki: "If you're going to use my character as one of the Sega All-Stars, can I have the Sega All-Stars represented in Shenmue III?"
Sega:

That's why revenge is a dangerous game. If we prepraed too long, we might not have a chance to do it.

They also say "Those who pursuit revenge should make two graves.", though I don't understand why. You'll either go down with them, or you're doing it wrong. That and depends how many people stand in your way.
Some people into that though ... SM thing.
That's just what they're into, I suppose.
