Probably just poor design.  Mechanical switch keyboards are the best, but tend to cost quite a bit more.  This one is probably like most keyboards, under the keys is a big plastic or rubberish sheet with a bunch of copper lines.  When you press a key it causes the two lines under that key to contact and that generates a signal to a chip that translates into a key code that represents a give key.  You could probably pop the key off and take a dremel tool or some sand paper and sand the end down a little, test and repeat until it's less sensitive.