In both monitoring and config management, the majority is right.

Monitoring: you don't want to have all your applications and even scripts run a thread to listen on a dedicated port to allow pulling. It's bad for security, code complexity, configuration complexity (all those ports) and reliability (when an application stops the datapoints are lost).

Config management: with a push model you can easily end up having 2 developers push to the same system (or to systems that should be updated in sequence) in an unmanaged manner.