If I wasn't working a regular job, then I could write three hubs per day, if that was all I focused my energy on. Since I do work a 9 to 5 job, I can't even write one hub per day. I want to ensure the hubs I write are accurate and of good quality, which limits me to one or two hubs per week at the most.
Writing good hubs is only half of the process. You then need to figure out how to backlink to your hubs to generate traffic. Look up one of the many hubs on this toppic to learn more about this important part of the process.