I think that when people choose his profession they should look at three factors:
- they should like doing things which are required in this field;
- there should be a smaller than in average amount of candidates and bigger amount of job proposals in that profession;
- it should not be a short-term decision, the chosen profession should survive for at least next 100 years.
Second and third factors are good for Blockchain developer, but you should be sure about the first.