For more than three decades, an unlikely coalition of corporate philanthropists, educational technology entrepreneurs and public education bureaucrats has spearheaded a brand of school reform characterized by the overvaluing of technology and standardized testing and a devaluing of teachers and communities.

各位老师好。这是网上看到的“2019年6月CATTI二笔实务真题”中的一段。粗体字overvalue和devalue都是动词，请问为什么两个词的ing形式就变成名词了？所以后面可以加of？