Some pundits are saying that bitcoin is a ponzi scheme and it wouldn't last long. They are either ignorant about it, or don't want you to earn money. Bitcoin has made a lot of people rich over the past one year or so. It is still the best long-term investment out there.
The person who says Bitcoin is a ponzi scheme has no deep knowledge about Bitcoin because I think Bitcoin is a digital asset that must be properly understood to understand how Bitcoin will make your life better for the future.