There is nothing immoral about copying software. It is not theft in the moral sense because in actual theft the person no long has what you have taken. That's what made theft "theft" in the Biblical sense.
Well.. If you want to get all biblical on my ass, I'll just have to educate you to the meaning to liberty and what it fundamentally means to "own" something.
For instance take a apple (red apple, not a computer), it fell from a tree in the wilderness (not grown or cultivated by man) and some guy walked over to it and picked it up and ate it. At what point morally does that apple belong to him?
When it was growing? When it fell out of the tree? When he picked it up? When he ate it?
Well the answer is of course when he picked it up. The actuall act that made the apple his is when he put forth the work and effort to retreive the apple.
Now if somebody took that apple, does that apple belong to the new person? No it does not. He did not hurt the man, there are plenty of apples, but morally it is still wrong.
It is the same with software. THE WORK that went into the creation of a product is what makes it a person's. NOT the potential profit off of it.
That's what liberty is. It's the ablity to control and use the results of your work as you see fit.
Software is the results of a person or a bunch of people sitting down together and producing a new program from their effort.
diversion to GPL/OSS land:
The same goes for GPL'd software like Linux. If I produced a peice of software and release it for free under the GPL, it is still my software in every sense of the word. I can if I want stop my personal distribution of that software and release it and develope it under a commercial liscence. That's all within my right. I created the software, without my work it would of never existed.
Of course if somebody had already contributed to my software under the GPL, I would be forced to honor his code and my modified code as still pure GPL. Since then he put work into it ceases to be mine alone.
By your reasoning if MS stolen code from Linux and stuck it in the NT kernel to improve performance and stability. Just as long as they thought that it wouldn't harm Linux finacially (after all Linux is such a minority)
Now back to closed source stuff:
Also you would be violating the agreement and contractual obligation you originally agree to when you purchased the software. You said that you would not copy it and distribute it. If you did do that you would be breaking your word, since if you declined the agreement you would of never obtained the software in the first place.
If you didn't purchase it initially you would be aiding someone in there breaking of their agreements.
This is immoral.
What makes it immoral is NOT the potential finacial loss or damage to the person who you are violating by stealing software.
It's that he/they put forth the work to create it and by violating their wishes you are violating their liberty. That's what makes it immoral.
Now you could (and did) argue that companies like MS originally stole much of the software that it uses.
My response is that:
1. (for all forms IP) True they did. However most of it still did orginate from MS. That is why I don't get pissed when people in turn steal MS products. However, like moms always say: Two wrongs don't make a right.
2. (for MS mostly) People stealing MS software are in turn supporting MS efforts. MS remains dominate thru force of numbers. Their software is inferior, but they still own 92 or so of the Desktop market. Many people who buy games and purchase hardware to run with/on stolen MS software. This incourages hardware manufacturers to support MS and not support other alternative OSes such as OS X or Linux.
You are helping MS, and rewarding there orignall theft of IP.
Proof:
Corporate version XP. Why didn't they use a proven method of software liscencing servers like every other closed software producer?
How many people complained that they never would use XP due to the restrictions. What was the general answer: Corporate Edition.
I believe this was a calculated move on MS's part(<-edit):
Because then a large number of computer enthusists would be forced to run older versions of win98/winME/win2k. Thus reducing the impact that XP would have on the market place.