Doctors, Lawyers etc usually work and bill by the hour. Be a top software consultant and you can make $200k-500k a year as "easy" as those other fields. Of course its still not easy to make $500k a year, but it also isnt that easy for the other jobs you mentioned. You need to be really good, have good clients with deep pockets who have lots of work for you and its probably easier to reach that kind of money than with other jobs.