Telemetry creates a liability for the user for no benefit (and as Windows 10 demonstrates, the amount of telemetry is anti-correlated with software quality).

Even if we assume there is no malicious intent from either the developer nor their infrastructure provider (their initial telemetry attempt was using Google Analytics which is definitely malicious), it can still be coopted by a malicious actor who is able to observe the network traffic or compromise the telemetry infrastructure and put the users at risk.