You have brought up a very good aspect about enterprise software. Although at first glance, enterprise software is measured by a set of technical requirements (although not really that measurable ;-), it is certainly created with a clear and strong marketing purpose there.
Have said this, you have to give credit to some of those softwares, such as Oracle. Things like MySQL obviously does not provide the same level of strength (at least not currently).
But when a software is called enterprise, it is not just about techonology, it is about to charge companies that are at the enterprise level.