Just look, for instance, at FPGAs: almost all the tooling is proprietary, very expensive, and very buggy too. Or look at PCB design: Altium seems to be the standard here still, despite Kicad having made huge advances and by most accounts being as good or even better. It took decades (Kicad started in 1992) for the FOSS alternatives here to really catch on much, and only really because PCBs became cheap enough for hobbyists to design and construct their own (mainly because of Chinese PCB companies), and because CERN contributed some resources.
I'm not sure what the deal is with engineers hating collaboratively-developed and freely-available software, but it's a real thing in my experience. It's like someone told them that FOSS is "socialism" and they just reflexively dismiss or hate it.
Most of the incredibly well used robust open source packages are sponsored by large tech companies. The embedded space just hasn't had that kind of sponsorship.
You could say that about many other fields too, but then why do we have great tools like Blender, Krita, Audacity, etc.? Artists and musicians have great software skills, but electronics engineers don't? There's always been a huge overlap between EE and CS degrees, with "computer engineering" degrees coming about as a merger of the two fields decades ago, so I find this statement hard to believe.
Google tells me the average salary for a Mechanical Engineer is $95,675/year.
The cost of a single-user SolidWorks Standard license is $2,820/year [1]
You don't need to get big and negotiate a discount - if the engineer says they're 3% more efficient using SolidWorks, it'll pay for itself at list price.
[1] https://www.solidworks.com/how-to-buy/solidworks-plans-prici...
Sure, the company might not blink an eye at spending $2820 on a software license for the engineer to use at work, but the engineer himself probably isn't going to be able to fit that into his own budget if he wants to work on any personal mechanical projects at home.