First of all, this is altcoin not bitcoin discussion.

And secondly Bitcoin and Ethereum are two different creations. They do not focus on the same market applications or services.
Bitcoin was primarily build to handle cash transactions (and may someday even be recognized as 'real money'), while Ethereum is a complex blockchain based contract mechanism.

In my book Bitcoin is money, Ethereum is not. So market cap on Ethereum is not on their coin as much as on their blockchain solutions.