Monero isn't doing too bad. It has outperformed Bitcoin by a factor of 2. The price doubled between 01/17 and 03/17 from about $10 to $20 and doubled again from 03/17 to 05/17 to nearly $40.

Maybe it's not a good idea to compare Monero's market cap to DASH or Bytecoin (which are its biggest rivals). A lot of DASH is locked up in masternodes and a lot of early mined BCN is probably not being traded on exchanges. The actual available coin supplies for DASH and BCN are probably much smaller than the circulating supply figure shown on CoinMarketCap.