Be did have the BeBox that had a Geekport that Apple could have used to better expand Macs for.
There was this ARDI Exeuctor software that could run 68K Classic MacOS stuff in Linux, Windows, NextOS, and I think they were porting it to BeOS.
NextOS was a much better choice due to the OpenStep librarie shared with HP, Sun, Oracle, and others. It was forked as GNUStep and ported to Linux and other operating systems.
Apple has always been a hardware company that has the software integrated to the hardware. It is because they bundle both together than it works better than PCs running Windows from everyone and their brother making PC Clones. Even with the Hackintosh stuff not all drivers work and some Hackintoshes don't have things that a Mac does like OS updates, etc.
BeOS was made into a multimedia OS to challenge AmigaOS that already was a multimedia OS with Video Toaster and other stuff. BSD aka NextOS was more of a workstation/server OS and clearly the better choice.