There is a huge gulf between a quick project you hack together as a personal project, and a commercial-grade finished product that thousands of paying customers use. Don't assume anything is easy when you bring it to that scale. It's like playing around with your own boot loader and toy OS using some low-level assembly and C, and then claiming anyone could create Windows in a couple of hours.
The same goes for the open source suggestion. Go open source, ????? magic ?????, success! It doesn't always work like that.