Ferrari, Bentley, and Rolls are completely different. The fact is that you don't see them because you could afford over 10 mid-range MGs for the price of one Ferrari F430. They are too expensive for 99% of Americans, an MG isn't/wasn't.
I will admit that there is a small cult following for MGs, but its not the kind of consumer base you would want for a car to compete with Ford, Honda, Toyota, etc. The people that like MGs are similar to Lotus Elise or Mini Cooper fans. They can support a small-ish amount of sales, but its not what you want for a full sized lineup, which is what the Chinese companies should be going for.
Also, most MGs were horrendously unreliable. British car makers are known for how much time they spend in the shop.