What part of it is unprofessional? You specifically called out the language OP used - that seems totally professional to me. The overall message sounds like throwing a tantrum to my ears but that’s not what you called out. How do you think it should be worded?

[–] onlinepersona@programming.dev 2 points 9 hours ago

The "I cannot have faith..." sentence. It makes it feel like a reddit message.

I would have worded it more factually without questioning the future of the company and motivation of the employees by calling them "lazy".

Devin informed me that Windows laptops are mandatory and that there no exceptions. Unfortunately, this does not align with my requirements stated during the interview process: Linux or Mac are my operating systems of choice. Please consider informing future candidates of the tools they will be provided earlier in the process.

The assumption being made here is that the person actually stated their GO/NO-GO preferences during the process. Otherwise it is a waste of everybody's time to leave something so important to the day of signing.