Not taboo exactly, but definitely discouraged by hiring practices: generally the big studios want someone who can do one narrow task without handholding, and do

Not taboo exactly, but definitely discouraged by hiring practices: generally the big studios want someone who can do one narrow task without handholding, and don't put much value on broader skillsets. And like most creative fields there's typically more people who want the specific job than there are jobs in general. Smaller studios, indies, etc. are typically looser (or just can't afford to hire someone who only wears on hat) but they are also less likely to have a dedicated level designer in the first place.