The reason to go with pulse in the default options is a very pragmatic one: in the majority of upstream projects, this is the best maintained and tested option, even if other adapters are provided. Of course that's because it became the de-facto standard on Linux desktops. And then, once you run pulseaudio, it's best to have ALL audio use it, otherwise issues are more likely...
Of course, FreeBSD has no need for that technically. And I don't use it either (building my own packages with sndio or oss, with possible fallbacks to sdl, alsa, portaudio, ...). But I have one thing not working that way already, for remote audio with xrdp, pulse is the only option, and as all my ports are built without pulse support, it just won't work.
So, in a nutshell, you won't convince ports maintainers they should ban pulse from default options, it would likely cause worse experience for users of binary packages. To change that, you'd instead have to convince a LOT of upstream projects to have oss (or maybe sndio) as a first class citizen (again).