That’s probably because they have full metal cases, which are opaque to radio waves and thus they need to turn the case itself into the antenna. If you directly touch an antenna (make electrical contact with it), your body becomes part of the antenna circuit which a: dumps power into you (a very small amount of power, all it does is cause a local temperature increase which your circulatory system deals with automatically) and more importantly b: ruins the antenna’s radiating properties thus requiring some kind of expensive active compensation circuitry.
Something with a plastic case and an internal antenna (which is hopefully what we get) won’t have this problem.