My point of view is that if you want to use CL in your shop, you better have serious money as the people that can do it without blowing everything up are the same people that can find a good job somewhere else. Lisp is more like spell-crafting than house-building (Forth is like that too), so after a while, the system is more like a new language entirely. You have to get a team of highly disciplined engineers and it's not something the current state of the industry tend to do.