Good TPAs do a heck of a job in helping plan sponsors administer the plans. The only issues I see with these great TPAs is that as a group, their marketing isn’t good. That’s not such a slight because I feel other professional services firms (especially law firms) don’t do a job of marketing as a whole.
Nobody likes to be taken for granted, I know as I had a family who did that. I think TPAs are taken for granted because they don’t convey a message to their plan sponsors clients about their value and what they do to keep a plan sponsor’s plan in order. If you don’t let people know what you are doing, then they will probably have no idea what you are doing. If plan sponsors know what a great job their TPA is doing, the less likely they will make a change even it means not saving a few measily shekels and pissing off the advisor who wants to make a change.