Sam2:
I wasn’t saying that observant MO will eat in non-observant MO houses, or even count them for a minyan. I was saying that they will accept them as part of the community, despite the things they do that are contrary to halacha. Chareidim, for the most part, will not. I was not coming to judge what is the proper mehalech; that is a separate discussion. I was explaining why it is that non-observant MO are still MO while non-observant Chareidim are not Chareidim. One group is tolerated by the rest of their community, and one is not; so the former can still be considered a part of the community, and the latter can not be.