This has a real cost associated with it, servers, datacentre space, power and cooling, system administrators to look after it all, don't come for free. Not just money, the environment too.
I still doubt that the CPU/power/cooling cost of having systems infested with hacky enterprise garbage is its biggest drawback.
That crap also causes expensive bugs and huge maintenance costs (e.g. relatively simple programs that require a team of 12 programmers a month to implement the simplest feature).
[1] http://www.ibm.com/software/htp/cics/ [2] https://en.wikipedia.org/wiki/CICS - yes, "Initial release: 1968; 47 years ago"
It's the other kinds of enterprise systems that are crap and deserve no respect. Intranet apps in big corporations, the BS systems that always mess up your bills in services companies, slow as molasses web portals for big enterprises and organisations etc, ERP and CRM apps...