People keep telling me that a trait of entrepreneurs is focus. But what if an entrepreneur can create and realize 2 or 3 ideas at the same time? Why wait to finish/fail 1 and then start the other?
If you can LEAD more than one project and delegate the DOING to others, then yes you can pursue more than one.
However, if it's just you, then I recommend pursuing only one. That way your energies are not diluted.
It is hard for most people to energetically build more than one business at a time.