It is a pity you are being downvoted. I do linguistic fieldwork in a similarly remote region and, yeah, you learn pretty quickly visitors fall into about those three types.

I worked in two way geostationary satellite for years and learned pretty quickly what sort of groups of people needed to pay money for Internet in truly the most off the grid locations. The other major users not so relevant for PNG which I intentionally didn't mention are military/government. I guess if it's not "mining" in some places you've also got "oil/gas", which basically falls into the same category of resource extraction. Sometimes forestry/logging.

By the way, your discontent about missionaries shouldn't be centered just around "gospel" groups. Multiple denominations of Islam have pretty far-reaching missionary networks into seemingly faraway places.

Yep, absolutely agreed. There's even Islamic parallels in the kinda-fundamentalist-Sunni world to weird USA TV Christian evangelists if you know who people like Zakir Naik are.