Customers forgive a lot. They do not forgive being misled, mischarged, or quietly experimented on. Word travelled — it always does — and the churn curve developed a shape your retention team described, in a meeting they thought was private, as "the cliff". The product still works. There is simply no longer anyone using it who hasn't already drafted an angry review.
"It's not you, it's the eleven separate incidents." — A composite of 14,000 cancellation surveys