The mature but diminishing crowd that does mainframes however is more savvy as how to keep out the kind of fast-paced changes or radical expectations that in combination with widespread belief that unix programming talent is as common as dirt causes systems to be immaturely spec'd, designed and built and consequent problems.
It has nothing to do with the software, its all in the sociology.
$99 for a Windows XP Home Edition Upgrade is good value. Thousands for a Windows server license is ridiculous. Hundreds of thousands for an Oracle license are ridiculous when SAP-DB is free. Mainframes are even more ridiculous. Except for applications that were developed in the age of mainframes and that are part of IT budgets somewhere north of $50M/year, mainframes are uneconomical.