honestly, if i were hiring and heard this of an applicant (and didn't have reason to believe it was something else like salary), i would feel that we dodged a bullet.

(that may not be entirely fair, i guess i just tend to be skeptical of people who get hung up on languages.)

I don’t agree with you. Provided you’d persuade him that the company and tech are worth it, I think he’d be a good addition to most companies.

It’s a legit concern.

And did they refuse the job because of D, low salary, not wanting to move to the Netherlands or some other reason?

I could see a C++ dev giving this a try without hurting their career prospects, but C# devs are not exactly known for trying out non-mainstream technologies. If they switch for a couple of years MS will pump out a couple of frameworks and .NET programming languages. Fire and motion as such.

He wants to move to the Netherlands and he was quite explicit that he's apprehensive about D. It's true that C# programmers generally don't venture outside the mainstream.

I can understand this. If I had to pick a marketable/future employment language today, I would pick C# over D (I have used both).