I’m talking about the physical socket in the kernel here. Not a hypothetical one. You can send packets (literally pulses of electricity) down it, but you don’t know if anything happened until you get packets back. By default, this is around half an hour, basically far longer than any human would reasonably wait.
My point is, you have to set this or accept the default timeout. The default is more than reasonable, anything less than minutes — with an s — is unreasonable.