How many times you get a new project within 1 year? In my case, the answer is 5 to 8. So, using generator does not really save my time. Especially, the structure packed by these generators are always outdated. Taking a look at http://yeoman.io/generators/, you can see:
react-fullstack: 4 months ago
angular: 7 months ago
ionic: 6 months ago
...
They are too old for me.