Probably should be "management" can't be rational about programming languages because that's what it's about. The article isn't talking about a group of engineers coming together to decide on a platform, instead it's about a choice being thrust upon from from up high. That management is also an engineer but that's not really the key point.
Why would management care about tools?
In the first example, they didn't and recruited a CTO who made a tool choice that arguably killed the business (maybe it still ends the same with PHP, minus the experience of building a nicely architected system in Perl: what-ifs all around).
Management does need to care to ensure they hire people who will make the right choices (which is a careful balancing act of investment vs returns) if they don't trust themselves to do it.
CTO is management.
Exactly, when they do its a sign of bad management. The only case I can think of when this isn't true would be the difficulty in finding people willing to use/work in that language. But in all but the most obscure languages, this is probably given too much weight by management.