It’s all a matter of trust. If you don’t trust your developer to choose the right environment, then how can you trust him to build the best application? Trust is critical here. And, further, why would you dare impact your developer’s morale by throwing him or her into a language where he can’t be as productive or as satisfied?
A consequence of this line of thinking is that companies with architecture teams, don’t trust their developers. If you work in a company with 5 levels of architects, they really don’t trust you.
Does your employer trust you?