Why is Acrobat such an enormous application? It's all bloat. Don't come to me with the features that 0.001% of the people use. I bet the program could be 20 MB and nobody would notice. And a hell of a lot faster. It should open and close almost before you click the button.
Why is it so big? Because companies do use a lot of the functionality built into it. Heck, the company I am with has very few people compared to some organizations I have dealt with, and we use quite a few of the PDF distribution capabilities that acrobat provides. But, also remember, that Adobe ACROBAT is not designed solely as a reader. It is designed for the business/user which wants to control distribution of their documents, provide change tracking, add form capabilities to documents, and quite a lot more. The functionality I list above is only the tip of what acrobat can and is used for. The biggest thing I see people making the mistake about acrobat is using it as an "editor". Acrobat is NOT DESIGNED to edit documents. It is designed to convert your existing documents into a cross platform distributable document with the type of security or modifications you require. Most users think that a PDF document is meant to be a SOURCE document, which it is not (minus, again, form-based documents). You still require a word processor/3rd party application to create the base document.
Same with Office. Let's talk Outlook. All it does is email and calendar stuff. So slow. There's no need.
Outlook does FAR MORE than just calendar and email "stuff". Again, my small organization (~300 people worldwide) uses outlook quite often. We share calendars, exchange email, perform task processing and tracking, manage our organizational contact lists, conduct meetings, and quite a bit more with outlook. Plus, outlook is designed to interact with our user portal so we can share information between outlook and our web-based portal so that users can access this info anywhere in the world. I have yet to meet a program which can do as much as outlook is capable of, minus notes but we won't touch that monstrosity.
Same with any large mainstream software. Nero, Mcafee, Norton, Photoshop. It just doesn't seem like we are able to enjoy the processing power we have today. The more power we get, the more bloated programs get. And if the OS is bloated or inefficient, then we're instantly off to a bad start.
With more processing power comes more ability to perform. Application developers adapt to what their users request. The issue with power users is that all they want is something small but power users, as much as I hate to say it, are not the majority (Minus photoshop/video editing professionals). Nero added most of it's media processing applications to the Nero suite because end users requested it. Nero started as a very basic CD burner but with the change in technology came a change in the end-user requirements for what they hoped the application could do.
Now please, do not get me wrong, some of these changes should be optional and selectable at install (and in Nero's case, they are), but most of what is included has been requested. The vocal MAJORITY determine, in most cases, what is important. Look at Microsoft, the users complained and complained about vista (although I personally had no issues with vista) and now we have Windows 7 which is lighter and as fast, if not faster depending on hardware, as Windows XP.