[selamin]

I can't imagine that's a real deterrent is it? Using LESS with Foundation is fairly straightforward. Create an empty .less file and @import 'foundation.css'. Also, LESS and SASS have very similar syntax. There's very little learning curve if you're going from one to the other...

[illicium]

You can't use any of the variables or mixins if you import the CSS in your LESS file. The syntax is not the issue -- the tooling is.