A lot of what enterprise software does is manage complexity. Massive amounts of complexity from interdependent systems and 30 legacy customers with byzantine business rules and contractual obligations to use this or that data format on this or that protocol. Processes that involve hand-written paper documents that you aren't at liberty to change but you must somehow account for them.
Startups like to write new, shiny things. They like to "move fast and break things". They like to write a single "beautiful RESTful API" for their users. It's a totally different world.
When you work in the enterprise world, things like rules engines and BPMN and enterprise service buses and Java/Spring with its Factories of Factories start making a lot of sense.
I always bristle a bit when I hear "enterprise" used on HN. It's usually a pejorative, and I get the sense many people think it's just a bunch of overpaid consultants scamming a bunch of hapless dupes out of millions because they just don't know any better. Not accusing you of this of course, but there's an awful lot of condescension about the topic in general.
And then I hear things like "Oh you don't need enterprise software because you can use Gmail for your email now"...
I'd also like to mention massive waste of money in enterprise IT though. I have seen big enterprise companies buy licenses for products from a consultancy company which costs tens of millions per year and it never ends up being used ;)
Rewriting everything in a hipster / HN favorite language is obviously naive but there is a lot of money being wasted now in enterprise IT that could be saved and used more efficiently (like R&D and innovation). Enterprise is area ripe for disruption imho.