If adding telemetry is faster and easier than engaging with the customer, then you'll see projects that add telemetry that wouldn't otherwise have the bandwidth to engage with the customer.
In general, I think the best way to go is to ask in the installer or initial setup, whether you want to send telemetry, and have a sane default according to whether you gather potentially personal information (location? personal, commands run (without args), not personal).
Example Prompt: Send telemetry (commands used, version) (y/n)[y]:
