You're not the boss of me.
Back to the Future had pretty major reshoots, and even replaced the lead actor, and it's one of the best movies of all time.
World War Z reshot a huge chunk (maybe all?) of the third act, and it was still a decent film.
FantFourStic had major unplanned reshoots, even having to cannibalize the 3D Conversion budget to do them. I don't need to mention how that movie turned out.
Basically, reshoots aren't some kind of harbinger of a movie's quality, not even major ones. They're just a normal part of film making.