Smelly and no fun to handle!
Because it’s smelly and no fun to handle! Actually, steer manure has always been considered a good cheap fertilizer, and many old timers still swear by it. The problem is that uncomposted steer and chicken manure are high in salts, which can burn (or even kill) plants while raising the pH of the soil. Uncomposted manure is also offensive to your neighbors’ noses, unless you live on a large lot out in the country. Fresh manure can also carry diseases and parasites.
With the advent of so many great all-organic fertilizers, there’s really no need to add manure to your garden. You can get much better and more balanced results with regular feedings of organic plant foods, without the manure.
If you really want to use manure on (or near) your food garden, please use sterilized/composted manure. It’s much safer than fresh, and doesn’t have as much odor.