Even if a few kits had bogus info on the instruction sheet, it would still be a huge minority. Most kit instructions are quite useable, or can be understood well enough so any competent builder could solve any problem. I mean, one of the gifts from model building is problem solving, right?
And then there is the childhood to adult transition. What worked as a kid, doesn’t mean it will, or even should work as an adult. Chucking the instructions aside; picking parts off runners at random, rushing to get a model finished before supper, and basically building without a plan are all errors that should be avoided. Any build that is rushed will usually show it.