You can both appreciate Signal overall and be critical of some aspects.

What the user criticizes is due to sheer choices, which affect some users a lot; for example, numberless registration and full cloud backups can only be purchased with a Google or an Apple account, which clashes a bit with the privacy objectives.

And it's not a problem of not having the infrastructure to support other payment methods, since the donations support all the common ones, and there's now even a cryptocurrency integrated in the platform.

Disallowing and ostracizing other clients is a choice, they spent effort to enforce it (for example by adding mechanisms to recognize the official clients).