Not saying I agree that being closed source is in the public good, although one could certainly argue that accelerating the efforts of bad actors to catch up would not be a positive.
If that was true, then they shouldn't have started off like that to begin with. You can't have it both ways. Either you are pursuing your goal to be open (as the name implies) or the way you set yourself up was ill-suited all along.
When I was young I proudly insisted that all I ever wanted to eat was pizza. I am very glad that 1) I was allowed to evolve out of that desire, and 2) I am not constantly harangued as a hypocrite when I enjoy a nice salad.
It's not like they've gone closed source as a company or threatened to run off to Microsoft as individuals or talked up the need for $7 trillion investment in semiconductors because they've evolved the understanding that the technology is too dangerous to turn into a mass market product they just happen to monopolise, is it?