It's not about cloth or leather, both are nice, it's suede anyway.
More complementing the design of the sport seats / interior door trims, dash, center console etc.
I don't mind the steering wheel, it does the job and they have the sport grips.
An E39 or E34 M5 shares the same body panels as a cooking spec 520i, so I think it's the wrong car to complain about if you don't like the fact they share parts across the range... that's the way of cars unless you buy one off Supercar models, but even a lot of those have low end model parts in them, like infotainment systems, keys, switches, lights, etc.