I've tooled up to develop FOSS FW for Zynq based scopes and bought an Instek GDS-2072E for testing. Intital work will be on a Zybo Z7-20 and MicroZed. I'm also going to try to build it on a Terasic DE-10 if possible, but that's for software engineering reasons.
The project got stalled by a $$$$$ TEA binge which forced a complete reorganization of my bench setup, as in rip it all out and start over. It's almost done. I'm in the process of setting up the parts bins and storage for work in progress. For various reasons, I'm limited to a 7 x 10 ft space which is shared with a bunch of computers, five at the moment, but I just bought an 8 port KVM switch I'm trying to find a place to mount. So the bench is really just a 4 x 7 ft space.
In general, I agree with Mike's view. However, if an OEM found themselves selling a bunch of scopes to people who then installed FOSS FW, they might get interested. But only if it meant that they didn't need to develop DSO FW themselves. Adoption really depends upon the relative quality of the FW. My motivation is very simple. I'm fed up with all the bugs even in the A list gear. I had a chance to try out a couple of $20K A list DSOs. I was not very impressed.