[alboy]

>you end up in situations where it's suddenly justifiable to let developers use technologies unsuited for the situation because they're "fun" and "interesting" to use and keeping them happy means they're more "productive"

Well, companies already do that and justify the practice as something that selects for more passionate developers and makes job postings seem more attractive. Exhibit A: YC's very own Paul Graham wrote "The Python Paradox" [1] back in 2004.

[1] http://paulgraham.com/pypar.html