This is how this letter reads to me: Woohoo, we got acquired. Thanks a lot for bringing our valuation up buy trusting us. We started $service to solve a problem that matters to you. Because of that we're joining $totally_unrelated_product. Thanks for all the fish.
"Because of that we're joining $totally_unrelated_product. And damaging the ecosystem that allowed us to get to this point."
It bears repeating that every time one of the acquire shutdowns occurs it makes users that much less willing to take a chance on a small startup. Even a shutdown like this that isn't screwing over existing users reminds everyone of the pattern.
Hmmm, maybe I should start ending this, or every message, with "Sarbox delenda est".
(Sarbox must be destroyed (https://en.wikipedia.org/wiki/Carthago_delenda_est) ; more specifically, this last nail and quite a few others need to be removed for the casket that the normal IPO was interred into.)