Agreed, and notice that I used a pair of quotes in one of my above posts
But for now, this kind of things doesn't exist, for obvious reasons: we don't have TI's private key (and basically can't obtain it through indirect means, as you know), so we cannot produce an OS that the Nspire would accept
Making our own OS is a fully legal purpose. But TI doesn't want to let us do that. And even if we were able to trick the Nspire into accepting the installation of an unsigned OS, we'd also have to trick the boot2 into launching the unsigned OS, which adds a level of difficulty.
I did not write that it's possible or impossible - I don't know. But it's hard, and highly dependent on the boot2 version, too.