How are you triggering the machine to PXE boot? How are you recovering from situations where the machine becomes unresponsive or needs someone to look at a console to see why a failure occurred?
Having the ability to remotely reboot servers is good, even in a “cattle” environment. Being able to pull temperature sensor data from servers is useful in a data center environment. Having an out of band console available can be helpful during incidents and outages, or with remote sites where there’s no tech that will be there. BMCs are useful in a large scale environment.
You must realise that potential 90 day downtimes just aren't acceptable in some domains.
Just because most BMC implementations are bug riddled shitshows, that does not mean the concept of a BMC is bad. OpenBMC is the exact right solution to the problem of bad BMC implementations.
Of course, you've signed up with that name just to issue decrees about IPMI being bad :)
