Technical writing: can a creative writer become a technical writer if obliged to, or not? Why?

Yes, I believe so, writing skills are transferable.  I firmly believe that.  Now there may be a fair bit to learn: the technology, format, brevity, logic, clarity, and interview skills, plus dealing with the deadlines.  There are also the intangibles of learning who to get the information from and how to get it from them, plus the requirements for conducting research.