Well, not every plague leads to pro-smallfolk reforms. Even Yersinia pestis is no guarantee to pro-peasantry reforms in our own world. Bubonic plague was devastating every time it struck, but the devastation of the outbreak of 541 didn’t lead to the same thing as the Black Death. There’s social factors, the evolution of philosophy, sheer population concerns, and so on.
I can’t tell for certain, but I’m thinking Bloodraven had a hand in it. Bloodraven passed edicts to stop people from leaving their land, but obviously, he lacked the ability to enforce it. He could more easily, however, stop nobles from raising wages to entice peasants to move to their land. Any smallfolk who tried to organize were likely executed as Blackfyre sympathizers (if Haegon ran on a pro-smallfolk platform, that would be an amazing wrinkle, but I’m going out on a limb and saying that won’t be happening).
It’s not all him though, the drought made the land itself less productive, which meant that the smallfolk labor didn’t have the same premium in the years following the Great Spring Sickness as the European peasants did in the Great Spring Sickness, and Dagon Greyjoy’s rebellion distracted the peasantry from wielding any power what with the danger of being abducted and murdered.
Once all that was taken care of, populations stabilized enough that the opportunity had sailed, and pro-smallfolk reforms would have to come from some other source.Again, however, this is all speculative, and the answer might be something else entirely that we just don’t know. You might want to ask @racefortheironthrone for a second opinion.
Thanks for the question, Anon.
SomethingLikeALawyer, Hand of the King
Well keep in mind, the Black Death didn’t lead to pro-peasant reforms. In fact, it lead to the opposite – the nobility and the monarchy tried to crack down on uppity peasants and restore the status quo ante plaga, and then the peasants rebelled, and were bloodily put down.
But the thing about even failed rebellions is that they make people nervous and unwilling to press the issue. So while there weren’t any legislative breakthroughs, quietly the nobility and the monarchy let serfdom lapse and tried to woo agricultural labor with more rights and better terms on their tenancy agreements. Likewise, over the long term, the cash that burghers in the towns and cities were making eventually translated into bribes to get more and more generous charters that gave city-dwellers legal and political personhood.
So while nothing happened legislatively until Aegon V’s time, the fact that Bloodraven wasn’t able to enforce his edicts meant that a lot of peasants got off the land they were bound to and got to a city or town where they had more personal freedoms, and I’ll bet dollars to donuts that when the drought ended and the nobility needed more labor, there was a lot of quiet and not-so-quiet renegotiation of tenancy agreements.