I guess the question is: if it got more expensive, would that mainly result in people no longer being able to vacation abroad, or just not doing it because they don't think it's worth the money, even though they can afford it?
If it's primarily $400k+ software developers who currently vacation abroad, then that wouldn't be that strong of an argument against removing the tax incentives.
I am not opposed to a more progressive income tax. In fact, I firmly support higher income taxes on everyone. I could never run for political office in the US because how will I ever walk up to a constituent and say "I want to drastically increase your taxes?" and at the same time walk up to public sector employees and say, "I want to take away your benefits".
Yes, we need to address climate change. However, I think we also need to encourage travel so we can facilitate movement of people and ideas across the world. Not everyone who travels will change the world but I'm sure it can't hurt.
If it's primarily $400k+ software developers who currently vacation abroad, then that wouldn't be that strong of an argument against removing the tax incentives.