Certainly there are people who "peddle" Christianity and use "ministry" as a means of gain. But hirelings like that are usually easy to spot for anyone with an ounce of spiritual discernment. Hirelings have long been an issue since earliest times.

My little ministry is a labor of love and I never pass a plate during chapel services, but I do make a little "offering box" available to those who wish to help with expenses, because it involves a lot of travel and resources to do what I do.

I think a lot of so-called ministers are performers who expect to be paid like rock stars for thrilling audiences and whatever. Perhaps this group's argument is really just a backlash against those "performers."