Okay, once again, someone help me out here...
What, exactly, did Pope St Pius X do, to "purify" the Mass? What changes did he make? My assumption would just be "none".
If he called for greater participation --- as he said, "pray the Mass" --- that is not a "change" in the Mass itself. I know there are various schools of thought on the desirability of a "Dialogue Mass", but I don't think that Latin responses, such as the altar servers make, are beyond the abilities of anyone with proper priorities who has a hand missal in front of them. (When I served the TLM a couple of decades ago, I always had to keep one of those little "cheat cards" in my hand, after all, the priest isn't required to memorize his part, why should the server be?) That is not terribly difficult Latin. People learn how to do various jobs, play sports, drive cars, cook from recipes, do math, learn basic historical and geographical facts, knowing the basics of the TLM shouldn't be any different. It's all about priorities.