in my opinion," 寂寞" in" 甘于寂寞" might not completely be the same as "loneliness". these enthusiasts probably are not alone as we might think of because they are devoted to science in which they have to deal with many things.
Don't ever try to mean "loneliness". It's a very personal thing. I don't see any point linking "the ability to handle loneliness ( it's not your business after all) with the work ethics of any kind. "Tough" might be a better word in its place.