Yes, I can see that is a good reason. And I think, so long as there is a traditional in-code way, then you can have options for both parties. I do see a trend - as part of the devops movement - where developers take on more operations roles, and ops does more work in code - that the in-code approach is likely to be favored by many. 

We currently use the New Relic agent, and it is my understanding that Jboss ( possibly Wildfly too) can only run one agent at a time? It would be difficult to convince my team to drop New Relic for Hawkular. And, as mentioned in the initial thread, our use for Hawkular is more about monitoring and capturing in code.

I know that, at this stage at least, Hawkular is very focus on server and system monitoring. Should you wish to explore further the possiblity of monitoring/capturing and alerting from more user-defined metrics and events, you may wish to consider using something like the jbpm/drools modeller. The idea being, a hawkular admin could define the model, then - again possibly re-use from drools - alert rules could be described using the user-defined model.