There is probably some underlying cause to both trends, something like "there are people who tend to be really ticked off about 'this operates slightly different in two different environments', such people are more likely to (a) use spaces and (b) have an engineering-type job that pays a little more." Another possible correlation would be "people who are more worried that they will someday have to SSH into a machine where they have not yet configured an editor in order to insert debugging statements into the live production code, tend to come from DevOps backgrounds that earn slightly more, and also tend to favor spaces instead of tabs because that damn default tabstop is 8 and I can handle 2, 4, and maybe even 3, but 8 is too damn high..." or so.
I personally really preferred tabs in my youth as a sort of nod to democracy and "everyone can set their tabstops however they like!" -- and it was Python that finally got me to use spaces instead, with the "hey when you want to do multi-line stuff" arguments[1] and PEP-8 and community agreement and such. But I do miss my little tab characters a lot.
[1] You know, stuff like "If you want to do multi-line stuff, then you need to keep a conceptual split between using tabs for indentation but spaces for alignment; and if you're using spaces for everything then you don't: you can even use your tab key to insert many spaces at once. So it's tab-tab-tab-hit-space-twenty-one-times versus tab-8-times-then-space-once. Worse, if you screw up the mixed tabs-and-spaces format then you won't know about it unless tabs are clearly visible by default, which adds visual noise to your file..." etc. etc.