Because it received best value award from Fine Home Building and is quite inexpensive.
EZ seems expensive to me. When I eval'd Festool vs EZ, I compared the costs and decided that Festool was the best value for me and a more coherent system. With EZ, I would have had to buy the components of a system and integrate them myself. With Festool, they are designed to work together.
One deciding factor was that I didn't have any power tools that I thought were worth keeping. If I had a lot of good tools and wanted to save bucks, I would have gotten something like a Red-Line guide. With good tools and if I didn't want to save money, I would have considered EZ.
Simple as that.
Regards,
Dan.