Why is 'disable_existing_loggers': True when using Sentry?

[cristobalmackenzie]

Why is 'disable_existing_loggers': True when using Sentry?

We just spent a ton of time debugging celery worker/beat logging issues until we figured out this setting. We started a project with use_sentry: y but haven't completed the sentry setup, and couldn't see any logs.

[browniebroke]

I don't remember if there was a specific reason, to be honest. Seems to be coming from #1820

Feel free to send us a PR to change it with an quick explanation of why we should chnage it, I'm particularly interested in seeing with an example of logging with before/after.