In the restaurant kitchens I've been to (small sample size), it was HOT. We're talking AC running on full blast, and it's still very sauna-like.

I understand that the lack of insulation might be the cause of this, at least partially. But since it's already typically very hot in the kitchen, I can see why makers won't add external insulation: the unit passively losing heat might not be a real issue in production.

(Re: ability to shed heat: I know confectioners need high level of precision in temps, the rest of the industry likely doesn't have this as a hard requirement.)