While a doctor making over $200k a year may seem unreasonable, there's a couple of things I think are important to consider:
- Doctors (along with most other professionals) have to spend 8-12 years of post secondary schooling which is foregone income.
- Most doctors, dentists and medical specialists accumulate hundreds of thousands in student debt that needs to be paid off after they've graduated and they've started practicing. 
- We live in an age of capital and labour (especially for the talented) mobility where you can move abroad easier now than ever before.

On a side note, I have 5 friends and acquaintances that recently finished med school (late twenties/early thirties) in the last couple of years and 4 of them have already moved to the USA. Talk about tax fairness all you want, but trying to convince anyone to earn half or a third what they can make down South and pay a less in taxes rate than Canada isn't going to keep a lot of young/new doctors here.