Because this one is built with one thing in mind: making it so simple that your mom can use it. Even the combined market cap of all Cryptocurrencies to date still only represents a small fraction of our financial transactions and monetary system (http://virtualrealitytimes.com/2017/05/30/chart-bitcoin-vers...). This is far from mainstream by any means. Nimiqs browser-based approach and clear focus on ease of use brings blockchain technology to everyone, everyday.