At a certain point, you realize that people in tech are constantly promoting the holy grail. So you buy into it, learn it, and then see that it has different, or even very similar weaknesses to the old tech. Also, you begin to realize that domain experience is a very powerful thing.
So, I would rather be happy, operating in the 'zone' with the platform I know, doing 20% more work to hack around sub-optimal language feature, than spend time in distress, trying to wrap my head around a completely different platform, all because someone on my team is obsessed with the new flavor.
(for the record, I've been on both sides of this)