And note that to me this is not really a bootstrap, because we're not using jc1 in any way -- it's just built to stress test cc1! So your stricter definition of a bootstrap is not really what GCC has been doing for years. (Not that I don't understand your different definition; but it's just a matter of semantics).
I agree that the compilations of cc1plus and the other front-ends aren't really part of a bootstrap and that we've done them for mostly historical reasons. Luckily, they are fairly fast ...