Technically it is since abandonware has no legal meaning, at least in the US. Nobody can argue this example of copyright infringement isn't a moral good unless they are just arguing from a "you must always follow the law" perspective.
As Ross Scott says, there are no good reasons, only legal ones.
Is it even piracy at this point? They purposefully took that version off the market, shouldn't the old version be made available as abandonware?
Technically it is since abandonware has no legal meaning, at least in the US. Nobody can argue this example of copyright infringement isn't a moral good unless they are just arguing from a "you must always follow the law" perspective.
As Ross Scott says, there are no good reasons, only legal ones.