Even so though, it's not like their poaching is hurting anyone. The Jarl can hardly eat every deer, now can he?
Just ask Bambi.
Poaching has very little in-game effect, other than running into the 2 scripted "Poacher"s who try to kill you, (That works about as well as the "Assassin"s, and Theif"s.) presumably to cover up their crime. Probably as more evidence of Corruption in the Rift, it's mostly a feudal anachronism that's not very well pursued by the dev team. Any Crime results in a Bounty, and Fine if there's any witnesses, but not only can you shoot deer, and elk right in front of the guards, they're also often seen leaving their post to attack foxes, and other game which aren't even hostile.
Back in the day, Meat was a luxury, and the poor only had it on special occasions. That was before there was a McDogfood on ever corner, and ranches of industrial beef, and chickens to supply the whole system. The concept of Poaching was a major reason for this, even farmers, and herders only had meat on special occasions, when they slaughtered a Lamb specifically for it, or one of their Milk/Egg producers accidentally died. Unless, of course, you were a Noble, who owned the land, including the game, and people living in feifdom to it. Then, the price of poaching was usually Death, immediately, without proof, nor trial. You didn't see meat sellers in every city for this reason, either. If you took it to the city, it went straight to the king. it wasn't until the Renaissance that you actually saw Butchers.
Of course, TES isn't set in this world.