If a private business requires that you pledge allegiance to Islam and denounce any faith you might currently hold in order to eat at their food counter, you’re ok with this because it’s private property?

Yes, I just wouldn't eat there, because I'm not self entitled like you. Now, if we're talking about discrimination by government entities, that's a different discussion, but the right to discriminate is part of the first amendment right to association. You're the one acting like a liberal, as you want to carve out exceptions for things that you want. The problem with that mindset is that's exactly what leads to things like trannies in women's sports. If you can't discriminate against race or religion, then why not make discrimination against "gender" illegal? On the other hand, if discrimination was fundamentally legal, then there wouldn't be protected classes, and private entities, like private schools, could choose not to allow such things. Your position is much more destructive than you think.