I like so many others use blank spaces to organise projects. Having only 1 heading level means the spaces are important, depending what it is you’re organising.
Please PLEASE make this an option instead of forcing the behaviour on people. Just adding a “clean up empty tasks” button, or a tick box per project to “automatically clean up empty tasks” would be WAY better. And then for reports, just have a tick box there too to “ignore empty tasks”.
It’s bad enough that hte TAB+N for a section thing reverses the workflow for that (as in you used to type text, then type “:” to turn it into a section, now you can’t type the text first because if you do and then type TAB+N it will make the NEXT line a section). But that AND not having empty lines is frustrating as 
Maybe even having CTRL+ENTER or some shortcut to add a blank line that’s not a task like someone above said would be good. For the sections I’d rather TAB+N turned the current line into a section so it matches the previous workflow. Theny ou just have to remember to hit enter then make a section, which most people would do anyway.