I always answer those questions the same way I would for my own quilts, which is usually in the "it's fine" category. As long as it's not structural. Then I'll recommend fixing it.
For me, quilting is a hobby. I have a job that involves a lot of stress and precision, I don't need that stress in my hobby. I also don't want other people to stress about it - I think (unless you're being paid) quilting should be done primarily for the fun of it.
So if you're the type that a flaw left over will stress you out - I'm assuming you're just going to fix it and not ask about it. If you're asking, I'm assuming you're somewhat like me and leaving it there is an option, and maybe you're even looking for permission to just leave it be. And for me...I fix some things and not others. Good enough is good enough and if it's good enough for me it's good enough for whoever I'm gifting the thing to. *I* will be aware of the flaw and try to do better next time, but I won't necessarily rip into a finished top to fix it.
"Nobody else will notice" is definitely something I've said over and over, and I say it because its TRUE. I know it's true because I grew up thinking both of my grandmothers were perfect quilters. It wasn't until I became a quilter myself and began examining their quilts with a critical eye did I discover that lo and behold...there are wonky seams and cut off points and 'cheater' bindings and all sorts of things going on in those quilts that I was completely oblivious to. I still love those quilts just as much (if not more) and if anything I'm ENCOURAGED to see that both of my grandmothers produced work with some flaws, because I know how well-loved and cherished all of their quilts are.
And if their flawed quilts are that awesome and that well-loved even after both of them have passed away...well then my never-perfect quilts are just as lovable too, and so are yours.
I guess the simple answer is - they ask, so I give my opinion, and my opinion is often to just move forward and keep it in mind for "next time". It's not heart surgery, nobody is going to croak if a point got lopped off here or there. If you're being paid that's something different IMO, but for your own quilting for your own pleasure or for gifts for loved ones...I think it's perfectly acceptable to give yourself a break and allow a little imperfection every now and then.