Considering that Reddit's capitalist shenanigans is what brought redditors here, having socialist devs is not necessarily a bad thing.
You'd probably also be shocked at how many communists are strongly involved in FOSS development, and just how nice and great people they are on average.
In any case, don't worry too much about it, their software is open source so if they suddenly turn evil, a fork is enough to fix it.
While I have to admit that I've been frustrated by the tankies during my short stay on lemmy.ml, I don't think that's a fair representation of their views.
Most I believe seem frustrated by a western world that seem entirely too content in accepting a narrative heavily biased in favor of laissez-faire capitalism and right wing narratives, to the extent that it has blinded them to the cruelty of regimes in China and Russia.
I think that in order to foster a fruitful discussion here and avoid the trenches that often form between differing political views on the web, trying first to understand and empathise with an opposing view is crucial. It's been a good heuristic for me at least, except in those cases where there is zero intention of even trying to understand each other (where just ignoring works well).