keep in mind that is pretty presumptuous. For whatever reason, some people are simply not interested in the same aspect of psychedelia as you are and that should be their choice to make. Not at people are cut out for deep introspection or philosophizing and when they're forced to think in that mode by a psychedelic it can be very "bad" to them.
I agree for the most part, especially concerning the actual term "bad drip" being generally thought to be possible for anyone is dumb. But it is certainly not impossible for ANYONE to have a bad trip. It happens all the time because people don't always want what they get from psychedelia.