That might not be a good measure, take a language related to PHP like Hack. The min salary for this language will be six figures because the only company that uses it is Facebook. PHP is a widely used language that your not going to have problem finding a job with.

StackOverflow's developer survey[0] would suggest that the original comment was incorrect. But I think it's an incomplete story for the reasons I and other respondents mentioned. The large supply at the lower end of the market depresses salary, but as one rises, salaries are in my experience comparable to any other widely-used language.

[0] https://insights.stackoverflow.com/survey/2018/#work-salary-...

I know some php devs from munich in germany which started at 64k per year. Others earn 70k+ per year. In agencies (wordpress i.e.) jobs start at 48k.