There are many packages (such as the BBC’s Domesday Project) which has long since stopped being supported by anyone, yet has great social value. Software such as this (and other old packages such as WordWise, WordStar, a large number of PC educational packages) have great value to developing nations unable to afford brand new machines with the most up to date operating systems.
A number of the companies behind such software have vanised with the copyright reverting to an author that often can’t be found.
Currently, it is illegal to reverse engineer, fix and release the software as either a patch or as an entire package. If the software is to be resurrected, someone has to physically sit down and re-write the code from scratch, emulating the original package. A waste of valuable resources when a fix could possibly be achieved in a short time.
Another reason behind the desire to reverse engineer are for protected packages. Again, if the company has gone under or cannot provide a method to remove the protection from a package (the company may have been bought out or if hardware is used, is no longer available), then a person who has a legal copy should be allowed to remove the protection for their own use. If the company behind it wants to distribute the fix, that’s up to them.