Historian here. That's a generalization. Manor lords did not "terrorize and pillage" the surrounding countryside.
Have you read the article? I can tell you it's a correct summary of an established views on medieval society, such as it is.
A common misconception is to view medieval serfs, free peasants and wage laborers as "oppressed masses" from a modern perspective, colored with romantic glasses from 19th century tales such as Robin Hood or Ivan Hoe. That's just incorrect.
Sure, there were plenty of peasant revolts (Jacquerie - https://en.wikipedia.org/wiki/Jacquerie) against the nobility. Both those were generally not against the foundations of the societal system from which manor lords derived their authority, but rather prompted by the precarious living conditions these groups found themselves in.
People didn't revolt because they felt "oppressed or terrorized", they would revolt when they got too hungry or felt unprotected.
The Jacquerie happened against the backdrop of the 100 years war. Warbands consisting of unemployed English, German and Spanish mercenaries roamed the French countryside. French nobility was pretty much powerless to do anything at the time. That's what prompted the lower classes, who felt unprotected, to engage in a violent uprising.
Most of the times, the legal framework which governed the relationship with a manor lord wasn't questioned since that's what provided a sense of stability and order.
Also, the "medieval age" spans 1.000 years if you use commonly accepted termini ab quo / ad quem (476 - 1453). But manorialism itself extended well into the pre-modern age up to the French Revolution and, depending on where you lived, well into the 19th century (Russia, serfdom was abolished in 1861). It certainly wasn't a catch all system: there were many variations and adaptations.