I'll attempt to clarify.
Printers are compatible with Jetpacks. The problem is that Jetpacks are not designed to be powered on 24/7 and thus are not a good device to use as your main home router. Printers are designed for normal home routers, not Jetpacks. Printer software also is designed this way too. You can get a Jetpack to support a printer but sooner or later something is going to go down or lose communication and then you will have to spend time bringing the network back online and reconfiguring everything. That proceedure is fine for some, but most will find it too annoying and look for a more stable solution.
Printers have different needs then computers and other personal wireless devices. A printer needs a nice and stable connection so that everyone knows where to find it on the network. A device like a Jetpack is constantly on the move or powered down which creates too many opportunities for IP Addresses to get mixed up as well as leave applications hanging.