It is not checking that is the problem, it is sending obfuscated information about the user without disclosure. That is unacceptable in any context, let alone a tool that requires an unprecedented level of trust.
Especially if you play any online games with ranked or PvP, they are likely doing a ton of work to prevent cheaters - and this information is necessarily going to be obfuscated, to delay the cheaters/hackers in their efforts to work around it.
From Anthropic's point of view, they have a class of "cheaters" they're trying to detect - people trying to distill their models. Those people are of course going to try to work around any detection, so you can't send that signal in clear-text where it is easily detected and blocked.
That doesn’t mean they are allowed to go beyond and scan user’s environment variables
What is the harm of that disclosure? If you are a company that wants to establish a firm basis of trust because you deliver a sensitive service, it is a necessity. I can't say with certainty that Anthropic doesn't disclose that they collect this info, but in any case, the way they've chosen to implement it does not lend credibility.
e.g. "Claude Code connects from users’ machines to Anthropic to log operational metrics such as latency, reliability, and usage patterns. "