I know many BPS parents who are very happy with the school. I also know a few DMIS parents with children in primary classes. They seem happy too !!! In fact all of them changed their kids from MES to these schools.

All said and done, I don't think you can judge schools on individual parents' opinions alone.  Some may have a good experience and some otherwise. In general, the standards of Indian Schools are better than, say, 5 years ago, but still a long way to go...