Guilt-tripping is a pretty common tactic for the WTS. The whole "could you be doing more" schtick is used for everything from getting people to donate more money to getting them to spend more time in field service. And the "some brothers have been discovered doing this" bit is also used when they don't have any real examples but they want to browbeat the membership.
They sound like one of those mid-level marketing scams, always pushing members to find more people to add to the pyramid scheme and learn better ways to squeeze more money out of them. It takes a while for many people to realize that they have spent their time funneling money to the top while getting nothing out of it for themselves.