As in any type of control structure. Mustache is explicitly a template
language without control structures. You can technically implement if/else
statements and for loops using Mustache's sections, but you can't have
expressions in your if statements. Template languages like Twig are more
like an actual programming language.
This actually seems like a point against Twig for me. I really hope we
don't introduce yet another programming language and added complexity on
top of our already extremely complex stack....
That said I'd hope whatever solution we go with can be slotted out by 3rd
parties in favour of another templating language.