* No public bug tracker
* epmd's security (or lack thereof)
* Can't insist that epmd be started separately (`erl -no_epmd` won't start epmd but it also won't start epmd's gen_server)
* Can't swap out epmd because while `erl -epmd_module foo` is there, `net_kernel:epmd_module()` is barely used. (Although I don't think it's interface is documented anyway)
* No built-in way to hook UNIX signals
* While the documentation itself is pretty good, it's presentation is lacking and it's difficult to quickly correct mistakes as you run into them
* It can be difficult to reason about when a shared binary will be garbage collected
* OS packaging (I'm thinking of Debian/Ubuntu) of Erlang and Erlang apps tends to be more harmful than helpful (old packages, namespace conflicts, etc)