While it is taking a while, there are legitimate reasons for that length. A game on pc is entirely different from a console game. It is NOT just switching buttons. Every system does things differently, so a different platform might require an entirely different code, method, or even coding language. This, in turn, results in developers having to redo or recode already existing code from scratch to fit the new system, or spend hours on bugs that only occur on that system. Porting a game requires immense amounts of energy, and for this reason many indie developers chose not too. ConcernedApe is an amazing person for even being willing to put this game on so many platforms. Even working hard, it is absolutely possible that it takes this long or longer, because even if you have "already made the game" porting takes a long time, and we should hope that comcerned ape wants to take his time and make sure the port is done right, rather than forcing out a buggy,corrupted port quickly.
TLDR; porting is hard, and takes a long time, because every system requires it's own stuff, and we shouldnt hate on devs for not doing it fast enough when they could chose not to so it at all. We are not the devs. We do not understand what actually is getting done and why that requires so much time. They do.