Are bot ratings off somewhat?

The issue is talent inflation. If every GM played just GMs in their whole career, the best GM would have maybe a 1100 rating. The same goes with the lower rated players. If everyone is good then improving on ratings is a lot harder.

It's because bot ratings are overrated (at least those up to 2 000, I don't know about those 2200+).

Everyone can beat a bot much higher rated than themselves. 

Bots are weird because of personalities and the fact that computers play weird.  

First, bot personality has strange effects on their behavior. If a bot favors a strategy that your favorite opening is good against, then you are going to win more often than lose, even if it is higher rated.

Secondly, bots just play weird. When a human blunders, it isn't a stupid move, it's just a move that didn't take in account all possibilities. A hung queen can still do damage to you if you don't notice it was hung, while a bot's blunders really hurt it for no reason.