[dagw]

Is WiFi uncommon in Europe?

It's pretty rare, and when they do have it it is incredibly expensive, limited or both. On trains they basically always have it and it's free.

(with the caveat that it's been 2+ years since I was on a plane so I don't know how things have changed)

[dTal]

Also worth noting that cell phones work normally on trains, what with them being on the ground, so you're not even at the mercy of the operator - you can just use your normal service.