I wouldn't say madness. But it is certainly very unfair to the rail industry. They should both be exempt or neither.
I know a lot of people are big fans of trains, but I'm not taking a train from Madrid to Copenhagen for business. It's not gonna happen. Madrid->Paris maybe. They're opening a new line that'll cover the distance in 5 hours.
But within countries trains are absolutely the way to go. At least here in Spain Even if you are on the train longer than the plane, there is no security-state bullshit to deal with at the stations and the experience is much nicer.