My issue with this specific concept is that lots and lots of people are lazy and instead of doing compassionate things, they "feel compassion" as a generic emotion through the use of meditation.

I studied Buddhism quite a while pretty seriously, and I know that a lot of the meditations involve practicing loving yourself, and your friends, family, community, and that these feelings of love are a core thing to have in your mind as your practice. But you also have to actually do things to help, it's not enough to be nice about it.

The Buddhist temple I took some meditation classes at practiced feeling good things towards people. The Episcopalians next door ran a shelter. It's not hard to see which is further on the path towards enlightenment, and it's something that seems like it's very very often missing from Western teachings.

And completely absent from self-help books about the subject, which are 100% self-centered. Lesson 1 of compassion meditation should be volunteering at a food bank, not learning to forgive yourself for your flaws. These things should be learned together, not in isolation.