1. Our community is not enterprisey.
problem #1 is a total cluelessness about what other people consider valuable and useful.
problem #2 is that when faced with someone else's problem which Lisp doesn't solve effectively, the response is a mixture of ``that's not a real problem'' and ``you're an idiot for wanting to solve that.''
In my case this is what prevents me from using Lisp.
1. Lack of most commonly used libraries to do every task.
2. No proper tooling support, No IDE's. No good build and maintenance tools.
3. Impractical approach to everyday problem solving which can other wise done in Perl.
4. Very high barrier to entry. And no effort from the community to make it easier. Reading documentation requires knowledge of a lot of things.
5. Overall complete refusal and denial to even agree these problems exist.
No body will use a language in which hiring is difficult. And who ever hires uses his own tools and programs with notepad. Frameworks, libraries, tools, volumes of programmers, good documentation, good forum support is crucial for any language to win today.
Merely language being good, does little for the adoption.