Why?

Datacenters don't (usually) smell of liquid cowshit, which is NOT AT ALL what you think it would smell like if you've only ever had the pleasure of cowpies.

Pigs are worse. They are unexpectedly similar to humans in this regard: their shit smells almost as much as our shit

Also if they make cheese there, the fermentation stench is very potent.

100% and if you've never had the experience you really can't properly conceive of how bad the smell is. It's not just stinky as in someone blowing up the bathroom, it's a smell so thick in the air that it can make you want to vomit and will likely give you headaches from the methane or other gasses involved. Depending on how it's being handled e.g. if they spray it on a field they use to grow feed for the cattle you can wind up dealing with levels that feel unsafe for weeks out of the year.

Cows smelly. Lots of cows really smelly.