"So unless you have top tier requirements It's easy to just throw hardware at a problem to make poor design go away."
This is so true. Can't count the number of places that have suggested we need bigger boxes to cope with the all the data Yet 10 minutes later you realise it is not just poor design, it's friggin' criminal.
System and user db's on the same disk. Data and log files on the same disk. and then of course the clincher it's all sitting on the OS drive.