Well to be fair he states his preference for expandability. I personally prefer the sleekness, the lack of investment in building it, the warranty, the 5k screen, the ECC, the testing of everything done at the factory, the perfect match of OS and hardware as well as the time I saved by not having to figure out all those weird issues. Makes me actually think the new iMac Pro (at least the base model) is pretty reasonable.

Why do you prefer ecc? I can't think of any uses for it in a Mac that isn't a server.

Which is a negative for many people, not a positive.