because you have to hit the keys so hard to ensure they register and the stop is so abrupt as paper thin plastic smacks against the metalI've heard others similarly complaining that the key travel being too low is like the feeling of running barefoot on a hard surface, and I agree --- on a good keyboard the actuation travel has to be very low to not tire the fingers, and a small tactile bump there is not bad, but the total travel should be relatively long and "bouncy" at the end to cushion the momentum of the fingers.
All rubber-dome keyboards are not alike either; some are stiffer than others, and some have higher actuation travel --- contrary to common advice, you don't have to "bottom out" a rubber dome switch if the inner membrane-actuating protrusion is long and "squishy" enough. Once it touches the membrane the switch actuates, but there's still a cushioning end-stop effect as the protrusion continues to deform.