> What's weird to me is Republicans say regulation is bad

What's really weird is that Republicans love markets and hate regulation, but don't seem to realize that every market is created by regulation. There's a complete lack of nuance among vocal Republicans.

Markets are definitely not created by regulation. Markets exist even in the absence of a functional government at all.

Any definition of "market" relevant to this discussion necessitates property rights, which require a functional government and a bare minimum level of regulations. We're talking about the Republican party, not prehistoric tribes, so a nebulous theoretical definition of "markets" that is easily satisfied by two people trading seashells is entirely unhelpful.

Open markets require standards, property rights, fair and impartial judicial system, currency, etc.

Without government, there can be no open markets.

Perhaps you're thinking of black markets.