Could someone explain why aMule, gnutella and soulseek are still maintained but shareaza isn't?

I just can't understand how aMule, gnutella and soulseek are still maintained but shareaza isn't...
I mean why have three programs when we can have one and select which networks to use?
soulseek should have been added to shareaza too instead of doing another frontend with nicotine

[ansani]

Hi! I'm trying to maintain Shareaza and I've released some packages. You can find new builds here: https://github.com/ansani/Shareaza.