[kristianc]

Even if they do standardize on vendors, they're then also dependent on, say, Oracle Retail supporting a given platform.

If you want your POS to talk to your marketing automation system, that's another integration and maybe another vendor who Oracle may or may not wish to support etc.

There's no way for a bank to standardize on vendors as it's back office systems might have been designed in the 1980s. If it wants to add an iPhone app or mobile payments, it has to rely on another vendor almost automatically.

Making these stacks work generates huge revenues for people like CA, Automic, IBM. Process automation is big business. Big meaty huge Fortune 500 companies held together with the software equivalent of sticky tape.