sure but wouldn't you agree that being in business at all, and not unemployed, is a bigger thing, and that the luxury to play is earned by success. if you can't pay people including yourself, I suppose you can always stay at home and play/experiment all you want.
It depends on your perspective. Different people are motivated by different aspects of engineering – lots of folks simply like "playing" as you put it, and the business's bottom line isn't important (except insofar as the business can employ them).
From the business's perspective, they want the best engineers they can get, regardless of the engineer's motivations — as long as they can get them to provide enough value to the business, it can be worth some trade-offs like having hackweeks, etc. It's the business's job to align the incentives of their workers, and sometimes this includes throwing them a bone in choosing a preferred language, even though it may not be the most efficient.
