What is the reason when making bait you want to leave it out for a couple of weeks to rot? I would think that a lure would draw the coyote to the set and fresh meat in a dirt hole would be more appealing to the coyote.

two reasons calling power and tainted meat is easier to digest. But fresh is appealing as well

Didn't know the part about easier to digest. I had a ground up cool whip container of venison in the basement not refrigerated for 10 days and believe me it has calling power. Had to get it out of the house could smell it through the container and the plastic bag it was wrapped in. Wife doesn't even want it in the back yard.

ya think?...lol

"Tainting" is normally done in an outbuilding or underground...on the downwind side of your property so odors go away from the house.
My "underground" is a dead freezer, where I control heat with a light bulb.

There is a lot to be learned here too:

https://trapperman.com/forum/ubbthreads.php/forums/11/1/Lures,_Baits_and_Urine_Archive

....and cats prefer fresh meat compared to canines.

I tend to do better with gland lures for cats over bait. But you are correct john!

I like to use fresh preserved baits in the early season and tainted baits later as it gets colder because of their louder odors. I do have a couple of meats that I did rot down and use these on flat and post sets where I anticipate a rolling or rubbing response. I use these as a change up or where I have a semi educated K-9 that won't work a dirt hole set.