Logic-less templates are a red herring and I cringe every time I enter a project where someone has drunken the Kool-Aid.
There's the rare fringe use-case where logic-less templates make sense, e.g. when you need to accept templates from untrusted sources (user editable) or when you really can re-use them across tiers to a significant degree.
In pretty much all projects neither is the case.
Instead, they quickly turn into a ball on a chain that constantly gets in the way and causes more problems than it solves.
This is my experience from encountering them in nearly a dozen projects and from having fallen for the temptation more than once myself.
Maybe I'm misunderstanding this, but you can do some fancy stuff with handlebars.js. You can 'foreach' through a json collection right in the template, 'if' 'else' statements and a whole whack of other cool little logic statements. So far I've not found anything I can't do in handlebars that I could do generating the page server side. Maybe I'm missing some more advanced cases or misunderstanding the term 'logic-less'?
As for bloated template code? I really don't know what you are talking about. Perhaps you just haven't seen well written mustache templates. My startup, Bagcheck, and Twitter (where I now work) have switched completely to Mustache. It really does work well if you use it properly.
Plus there's the whole thing that ‘logic-less’ is a big white elephant: templates need logic, or they quickly become unmanageably bloated and un-DRY. Being able to iterate and conditionally branch are fundamentals essential to templating languages, and so whilst Mustache is an interesting starting point, it's usually not the best solution.
Of course, the one benefit Mustache does have is parsers in lots of languages, allowing you to share templates across client and server-side — it'd be great if somebody were to invest time in producing (say) a Ruby version of Walrus, as it looks like a very useful tool from reading through the docs.