Why the hate for mcintosh amps?

Both

Say what you like about McIntosh but so far as I know, they have never imprisoned a Nobel prize winner like the owners of Cayin.

Why the hate for mcintosh amps?

 MC275 tube amps were great amps.
But there is no good reason to put an output transformer on a "good" solid state amplifier, it can only make it’s performance worse.
It’s a bit like using auto-formers on otl tube amps that can’t drive speakers well without them.

Cheers George

No hate for McIntosh amps here.

https://www.sothebys.com/en/buy/auction/2021/from-the-vault-property-from-the-grateful-dead-and-friends?locale=en

But there is no good reason to put an output transformer on a "good" solid state amplifier, it can only make it’s performance worse.

If 'performance' means THD numbers then yeah I would agree. However if 'performance' means SQ then I can think of a good reason - you want to drive a lower impedance speaker than the amp is designed for. Another good reason is that you have a much higher power amp than you need - the trafo will improve the dynamics in such an instance. If you don't believe me George you could ask Nige at DIYA he's built a battery-fed LM3886 amp with multi-tapped transformers on the output - they are part of the volume control.