I can imagine quite a few sources that I wouldn't want to direct traffic to even if they published something where I agree with the sentiment.
That smacks of voting for ideological correctness over truth or interestingness, a problem that otherwise intelligent people should be able to look past. What makes this site meaningfully different from the front page of Reddit if people will crap on an article because it comes from a source that doesn't align with their politics?
"Correct" is often a probabilistic assessment, not something a potential up/downvoter can determine absolutely.
The source is often an important input to that probabilistic assessment.
> That smacks of voting for ideological correctness over truth or interestingness
Different outlets of the same ideological bent (whether relatively neutral or not) can have wildly different editorial standards which produce wildly different reliability.