Its interesting to hear designers on a rant about capacitive buttons. Switches are the bane of most electrical engineers because they cost a lot and they have a finite lifetime. So generally they are thing that is going to 'kill' the product. And because they are both mechanical and have moving parts (in the non-capacitive variant) when they break the users just push harder trying to get them to work and that can crack traces on the circuit board and end the life of an otherwise working piece of gear.

Capacitive buttons can be 'tuned' (which is to say one can adjust how sensitive they are) somewhat depending on their antenna design and the ambient conditions. What is really hard for them is in a high emf environment (think lots of fourescents and shag carpets) there is so much charge available at your fingertip that even turned waay down they fire with the barest touch, reverse the circumstance like a modestly humid day out in a field somewhere and they are lucky if they can see your finger at all. If you're finger is wet (and thus charge will tend to distribute more evenly around you body) they are nearly worthless.

I recently saw some interesting 'piezo' buttons where they were effectively capacitive buttons but covered by a bit of piezo material so that you had to push on them to get them to activate. But while better in many ways, the cost difference between a button that is just a trace on the PCB (essentially free) and one that has a bit of piezo material in it (even if it only costs 2 or 3 cents) is easily someones salary when you're activating 500,000 devices a day.