corvus, what if the shareware enhances a piece of existing software? How do you know where to install it.
Not every shareware is an application. Sometimes they have to go in specific places. For example, suppose I write a server program that runs all the time without the user having to log in. Users don't always know where to put it, or how to make it start up by itself when you boot your computer. An installer can do that for you.
What about installing system extensions that need root privileges, to be available to all MacOS X users? Do you expect the user to manually change permissions, and to know where to place the extension?
Simples applications don't need installers, true. But it sounds to me like you believe all shareware is simple applications.
And BTW, when you run MS Office, which is not a complex piece of software (it's just big), it actually runs an installer the first time you run it.
I don't understand why this is a problem. Click-click, type your password, and it's done. What's the problem?