This is not the reason for the correlation. The p-value of the tabs/spaces connection is about 10^-13 (one in 10 trillion), and it can be found separately within each (large) country.

This does not mean the effect isn't confounded with some other factor, but it does mean it's not a multiple hypothesis testing issue.

You can explore the code and regression yourself! Take a look: https://github.com/dgrtwo/tabs-spaces-post