Many companies will simply not use ClojureScript, it's too niche and too hard to find developers for at the moment.

It's much easier to find JavaScript developers.

Many developers are capable of learning a second language. If they are stupid about hiring they will insist on experience with ClojusreScript. And lets face it most companies will do that.

Really? Good luck convincing good JS developers that they should actually be doing Clojurescript at work instead. Maybe you'll have better luck at a local frequent clojurescript meetups (probably doesn't exist).

I work near a team of people I'd consider "good JS developers". If I were to just go over to their workspace and say, "We should totally use Clojurescript", they'd look at me with a mixture of "LOL, Emacs" or "This guy's a loon".

However, if I were to give a presentation talking about how I took X and rewrote it as Y in Clojurescript, and the benefits of doing that -- time, ease of debugging, code readability -- I'm pretty sure that they would not dismiss it immediately. (Of course, this would require me to actually learn Clojurescript well enough to rewrite my JS things in it. ;))

Because parenthesis.

That's the most common objection, and it's the one that makes the least sense. If we were to count the number of parenthesis + square brackets + curly braces, we would fine that there is not more symbols in a LISP, just that they are arranged differently.