One of the most common criticisms to bitcoin is that it is a pyramid scheme or ponzi scheme. Whenever you argue with someone about this again, I found this argument to be the most simple answer (taken from another forum).
On the one hand, bitcoin is an admitted pyramid scheme, but no more than any other currency (even gold or silver). Use it or loose it.I have found no other short answer to defuse this recurrent ignorant criticism so fast. Instead of arguing with the other person, you tell them that they are 100% right, so what. Now you can focus on addressing the next criticism...
