Changes and complaints

Judging from the fact that VMware, NVIDIA and ATI do not seem to give a damn about organized distro integration and instead produce self-extracting sh archives that spew untracked files into one's system, it seems more like there is just one person responsible for the Linux package, and the remaining 10 members of the team know how to edit the Windows MSI.

Well, that's certainly sensible choice: this about how much marketshares differ thus it's prudent allocation of resources.

Meanwhile, it would not be all that hard to use [an own instance of] a potent cross-distro build system like Open Build Service to cater for a number of distros in two swoops.

Yes, it's possible, but it does not solve the whole problem. It's not as hard to build your package (well, this is a problem, too, but a [relatively] minor one). It's the fact that you need to [test] it. Single self-extracting sh archive solves this problem to some degree, cross-distro build system does not. And even single self-extracting sh archive requires a lot of distro-specific code to handle [supposedly] trivial things (like the ability to run per-machine or per-session background process).

All these things are just a band-aids and don't solve the core problem.