[welterde]

It only counts as working if you are ok with a giant pile of hacks and pain. Ever had to debug NAT-related SIP issues? Not fun. A lot of protocols fell out of favor, because they poorly interact with NAT (and stupid corporate firewall rules on the other hand so everything gets tunneled via https now..).

And wanting inbound connections is really not that strange a request. Maybe I want to host some website at home? How about a weather station/other IoT.. How about multiplayer gaming?

There are so many things that would benefit from being able to poke some holes in the firewall. With carrier grade NAT becoming more and more common you can forget about that, since you have no control over their infrastructure to forward any ports.