Why such a difference in the ranking of programming languages?

Question

Programming languages

On tiobe, java ranks 10 times more than php and javascript.
www.tiobe.com/tiobe_index?page=index
But if you look at the popularity on github and stackoverflow, they are approximately equal:
sogrady-media.redmonk.com/sogrady/files/2016/02/la...
Actually the question is: Why such a discrepancy in the data? And who to believe?

Answer 1

The difference is due to different data collection techniques. The TIOBE rating is based on counting the number of search queries containing the name of the language ( https://ru.wikipedia.org/wiki/Index_TIOBE). Github, I believe, is guided by the number of commits to projects written in the corresponding PL. Stackoverflow is most likely tag oriented.
To be honest, I see no need to focus on these ratings; the maximum that they are suitable for is to serve as an argument in various phallometric battles on the topic "YP1 vs YP2". In real life, it is better to focus on the quantity / quality of the offered vacancies (if you want to program professionally) or on personal preferences (if you want to program "for the soul").

Answer 2

Employers.