Because I liked this coin and wanted to pursue its development and also the other committed developers agreed with me.
Starting a new coin would have just give a momentum for one or two weeks, and then people would have left for a new altcoin... This is how things works in this space. As we're in a long term project, it doesn't matter whether starting a new coin or not: this coin is cheap, available and the hashrate is currently low... so it's the best combination for everyone (either trader or miner) to join now.