[alin-sinpalean]

Having worked both on borgmon and with borgmon, I can think of a few reasons why some (many?) don't like it all that much:

1. As already mentioned, the macro system (and the fact that its use is basically required to set up basic monitoring) has quite a steep learning curve. Prometheus doesn't have that and I personally would prefer it did.

2. It's not a service, so you have to set up your own instance, configure it, maintain it. In many engineers' mind this is just another hurdle in front of them launching their service.

3. As a software engineer (particularly new to Google) you might not expect to have to do ops work and carry a pager yourself.

Out of all three, only (1) is a valid reason to hate on borgmon. That and the language itself, which is almost a 1:1 match with Prometheus, are very different from your regular programming language. But given the choice between flat, simple metrics (which is what most monitoring systems give you) and the ability to have arbitrary dimensions and be able to work with them to build useful alerts and dashboards and troubleshoot quickly, I (again personal opinion) will always go with the latter.