"I have been instructed by our branch manager to inform you that Stifel can no longer service your accounts as long as no load funds are the principal investment in your account. The concern is that these funds do not generate sufficient revenue for the company>"

Well, at least they are upfront with the information. I suspect that most brokers would not state the reason in writing even if it were a factor.
Perhaps it is time to look for a new broker or mutual fund family?

Bob