So do they like Tesla or dislike Tesla? Only a year ago or so they rated the Model S as the best car they had ever reviewed; then there were a few Autopilot failures and some troubles with the Model X -- now the honeymoon seems to be over.
It's not that I think CR does a wonderful job with cars -- or with any other product that I'm familiar with -- but I think that their biases are more complex than a simple "they like who they like".
Model S was a fairly new vehicle, so in year one they only did the first part - there weren't many Tesla owners who were also CR subscribers who also have had the car for at least a year to generate a reliable corpus of reader ratings.
Things changed in year two when reader surveys started trickling in, with Model S owners reporting higher than average amount of issues, which impacted the overall ratings.
CR's own driving tests still earned Model S a "CR Recommended" badge, it just no longer came with a spotless 100-point score they've previously assigned.