I think the other thing that they will say (if they have any guts) is that this is a beta, and that the point of a beta is to get technical feedback and respond

I think the other thing that they will say (if they have any guts) is that this is a beta, and that the point of a beta is to get technical feedback and respond to it. Therefore, it is entirely unnecessary to take such a strongly negative tone in making this relatively minor and mostly incorrect criticism.