It's functionally close enough to a conglomerate though.

I'm not exactly sure what '"free market" cultist' is or if you're accusing me of being one. Modern economists don't normally align themselves with simplistic ideologies like "free market", "communist" or "capitalist". They're aware of the historical and modern usage of these terms but they tend to focus on areas that are far to specific for those terms to even make sense. You won't find a lot of economists that argue for complete Laissez-faire capitalism any more than you'll find real economists arguing in favor of classical Marxism.

There is general agreement that conglomeration benefits management more than shareholders. There's general agreement that they are more likely to arise under some economic conditions and that those conditions usually aren't associated with socially optimal economic policies.