Not calling you ignorant, but for workloads that a simple, untuned mysql installation is sufficient you can just build yourself a simple, default postgresql installation. Use chef, puppet, terraform,... to make that repeatable and the setup pain goes away.
True, Chef and Puppet kind of take the pain away between different linux distributions (which is good). But this would be aiming at a deployment.
However, one common use case (for me) is having to have a one-off install, which unfortunately kind of prevents that.
If my job needed frequently installs of DBs I would have probably gone this way, but it isn't, so today it's PostgreSQL 9.1 on Mac OS, tomorrow (more likely, a year or two from now) it's MySQL on Fedora, etc
Chef and Puppet can deploy just fine into a development machine - either a VM (i'd recommend this) or even on your host machine. I can't imagine any workload that's simple enough to be handled by a vanilla, untuned mysql instance and at the same time not simple enough to be handled by a scripted postgres installation. Things get different once you're getting to more complex workloads, but the effort of tuning a mysql instance to handle those is in the same ballpark as the effort of tuning a postgres instance.
