Vague personal anecdotes doesn't mean they are not from the real world.

You're taking someone else's valid criticism of the state of the therapy methods available today and taking it personally as well as unwarrantedly attributing it to a lack of sympathy.

You fail to understand that the goal of criticizing the therapy method is precisely so we may find ways to improve it.

What makes this single point of view a valid criticism?

Because, getting back to the original point, stating "Mental health treatment has come an incredibly long way, just in the last couple of decades" without offering any substantive support for this viewpoint (regardless of whether one's anecdotes are "real world" or not) is, in and of itself, a valid criticism. The onus is on the person making the claim to provide a rationale to back it up.

What makes it not valid? It would actually be great to have an answer to that instead of the parent's complaints