I've griped for years at people complaining about the schools. Yes, there is much about which to complain, but it isn't the schools failing a lot of kids so much as their parents are.
Both my stepsons attended Clements High School in Sugar Land (well, the youngest graduates in May). It is at or near the top of all public schools in the US, every single year. Perhaps their teachers are a cut above most, but I rather suspect it's more related to the fact that ~90% of the student body is Asian. Those Tiger Moms don't mess around. A couple years ago, there were 5 kids out of the same class admitted to Stanford. And their sports ball teams are universally atrocious most years. You can't drive a 5 minutes in Sugar Land without seeing after-school programs for programming, math, and science.
The youngest has a GPA of about 4.3 or so, has I-don't-know-how-many AP credits, made a 1480 on his SAT, and isn't in the top 10% of his class. He'd do fine at UT Austin or TAMU, but he can't get into either one because of his class standing. So he'll likely end up going to U of H, probably the 3rd best engineering school in the state behind UT and TAMU.
It's certainly more difficult for a bright kid at a "bad school" to find his wings and fly, but that's more to do with undisciplined kids causing distractions all over the place than poor teaching or "substandard" facilities.