Whilst their entitled to their opinion I believe the opposite. It's all done on autopilot, your sim ride isn't. MCC is about working with your crew, it has nothing to do with learning how to fly.
Most of my MCC (in a fixed base "737 type" at Simtech) was done with autopilot off. The only times I had the autopilot engaged was during the en-route phase of the LOFT and a few times to demonstrate capturing the ILS.
You're right, doesn't really matter what you do it on as it's just the MCC part that matters. However, I'd say that if you want to fly jets then it would help to complete your MCC on a jet type. I found the course filled in a lot of blanks about how jets operate. I'm hoping this extra information will help in future interviews.
To the OP: I can only recommend Simtech as that's were I did mine and have no experience of other places. I was very happy with all aspects of the course. 28 hours of jet operations in a very nice sim.