Mmm, it depends what you mean by 'excellent' I guess. If you mean great results, that is probably always going to be partly a function of where you live... if you mean ofsted outstanding, not so. If you mean something less tangible.... then I don't know.
I've seen that smug virtue-sad necessity construction before as a way to dismiss others' arguments on a few subjects, and I find it a little dubious. It's quite clever, because it seeks to locate other people's perspectives as fundamentally nothing more than the function of their own dullness, poverty or self-delusion, and it's quite effective as a way to silence argument or make people feel their arguments are already discounted, but I find it a little convenient.
Finally - you can't have a system where some people get comprehensive if that's what they want but also have grammars which they might try and fail to get into. What's left is not a comprehensive, when one key reason you might go there is if you failed to get in elsewhere.
The only way that system might be fair would be if any child, no matter how promising or otherwise at 11, could have access to the grammar, and do the academic subjects etc. So if Bill's parents think that, even if he'll never be awesome at it, he'd really like and benefit from Latin, and Annie's parents, who know she's very academic, think she'd rather have a focus on drama and sport all have the same choices and options, not determined by test result. But where you have a test, the choice is a false one.