For smaller companies, or companies that want to invest less in their technology stack IT department, it sounds like a better deal to have all services provided and backed by a larger computation corporation (even if that's not always actually cheaper in the long run).

If HP or IBM or SAP or Oracle wanted to do what, say, Dropbox does, they would throw effectively unlimited funding at the problem until it was solved. They might not even bother to market the result publicly, to avoid diluting their brand, but if they chose to do so, then the unfortunate small company concerned would probably be gone in a few months (assuming the large company didn't just litigate it out of existence because it was easier, if you're in a jurisdiction like the US).

Put another way, companies like Dropbox don't do well because they have a magic recipe that the big boys don't, they do well because they've chosen a niche where they're too small for the big boys to care about and where there are plenty of smaller businesses who will value and pay for that kind of offering because they don't have the same kind of resources in-house to do it themselves.

Edit... I should also mention Google, who aren't likely to be competing in the "enterprise" arena any time soon for a very different reason: they aren't set up to support that scale of customer. If you want to sell software to an engineering giant or a global services firm with an employee count in six figures, you don't show up with a few web pages and an e-mail address, you send a CxO or two on a plane to their head office to schmooze them, and then you appoint an SVP whose only role is to lead a large team of sales and support staff dedicated to jumping when that customer says jump.

Another point, is that usually each company have diferent processes, and it's quite difficult to make a one-size-fits-all (as in facebook/twitter/google). Intranets, and biz software usually need people to make custom modifications on each company. Usually the people in charge of this changes are not as competent as the ones who write mainstream software and you end with a lot of crap, which is almost impossible to stop due to the fact that there are very few good programmers around to make custom changes to every company in the world.

I work with a lot of large corporations and we have constant problems with the software I support because the imperative is to continually drop operational costs. We'll have a team we work with that is well trained, understand the software well, and keeps the software working at near 100% capacity.

Then suddenly one day they are all gone and you get the offshoring team that knows nothing about the specialist software they are attempting to support, if they have the capability to actually turn a computer on is surprising. Software availability drops significantly having direct impact on deliveries, costing god knows how much in some of these companies. Support on the vendor side (my side) turns into a huge expensive mess because now you're now writing instructions to the level of "when you take a poopy, remember to flush and pull your pants back up".

Because big companies never, ever get by on annoying, but functional software?

They need to absorb things so their sales team can say "oh we have X feature" regardless of its actual implementability and just leave it to the consultants to struggle and somehow implement a half baked solution that doesn't work in the end.

Oh but that's how they make money also. More products, more features, more crappy integrations = more service contracts, more consulting work, etc.

All a huge scam that enterprises are forced into because they don't want to be "left behind in the digital economy."

I face the same thing. I'm locked into using a particular GIS software package for my work, supposedly a central system accessible from any device. However, in practice they have 3 different apps and 2 different web interfaces, none of which have the same feature set. And often I want to use data that's accessible on one of their platforms to do processing that's only available on another of their platforms. And there are backend problems for which I've periodically been sending in support/suggestion tickets for a decade without any fixes. However, their marketing feeds are constantly bragging about new features and integrations. Why? Fixing their broken shit is harder work for less payoff. So they just don't. And they've got the patents, so they don't have to care.

It's actually useful to remember if you're a start-up chasing a contract with an enterprise. You might bend over backward accommodating BigCo to get their name on your books thinking you'll make it huge once "they" start using your technology only to find it never actually gets further than 2 people in Sub-Department-Offshoot, and while you might get to use that fancy logo on your marketing material, you'll wonder if the concessions and vastly undercharged overwork was really worth it because the payday of actually having BigCo use your tech throughout their stack never materialised (because it never really does, but it'll be endlessly dangled in front of you to get you to agree to put in a bunch of features for free).

1. Have huge bloated software that is hard to add features to, support, or reason about

2. Are based on a decade or more old software (at best)

3. Are being undercut by software that does probably less than 10% of what they offer, because nobody needs the other 90% of shit they pack in (but did because they added some customization or "feature" to the product whenever a big client came online due to some slimy sales guy)

Having deep integration generally makes for a smoother process.