Because corporation didn't deliver on promises. Trust was broken and their attempts at fixing said trust is meaningless given what they've already done to break said trust.
There's a difference in character between a "sorry we messed up, we fixed it" mistake and a "sorry we got caught, we fixed it" mistake. A pattern of the former often suggests the latter, but as far as I know Backblaze has no pattern of these.
Why is their attempts at fixing trust meaningless?