Because even if the statement was hyperbole when referring to the majority of the tankie population, it still rings true for some of them- an inconvenient truth that you outright denied initially and were forced to backpedal on/reframe.
Most rational people are going to see this, see someone obviously using hyperbole, see someone obfuscating reality to serve their purposes, and dismiss you outright.
Beyond that, while it IS hyperbole to say tankies as a monolith believe in executing political dissidents, it is NOT hyperbole to say tankies as a monolith continue to support several states which DO believe in executing political dissidents.
I wouldn't color myself an anarchist necessarily, but I do find myself increasingly believing that anarchists are, for the most part, some of the only internally consistent ideologues. Fuck all states seems to be the only reasonable position when all existing states fucking suck.