Most companies are not used to giving away their hard and paid for work to everyone for free, no matter how old it is. I would guess that most of the Amiga specific companies went out of business a very long time ago, so even finding someone who has the source code for any of that early software might be difficult.
I would guess that most of them have put the Amiga far behind them as an economic necessity and (if they were any good) if they remained in the business of writing software, they were forced to switch to Windows, MacOSX, Games Consoles, or proprietary software for businesses that for the most part all use only x86 hardware. They may not even have an Amiga any longer and might not have kept a backup of their Amiga source code. It is sad to think about the amount of Amiga source code that has probably been lost forever over the last 15+ years.
