The marketing is very good and this is arguably more important than the features of the coin. If you look at something like xspec with exceptional privacy features, you will see that it is currently going nowhere fast. Onion on the other hand is doing much better despite only being released half a year ago, this is due to much better marketing.
Not to mention the fact that owners are rewarded for holding and even incentivised to buy more by the same measures. The price will tank as soon as the 'airdrop' ends.