That sentence could be interpreted as
"pirating software" the action of stealing the game or whatever
"pirating software" as in the programs used to do the stealing
It could go either or both ways, but I wouldn't keep the topic open much longer just to be on the safe side
There have been bans before based on both interpretations.
The rules aren't really set in stone and some piracy-based discussions have been allowed before.
But if you're discussing on how to pirate, or trading opinions on the best pirating websites, or promoting or asking for help or admitting to pirating games/music/videos or other items that are currently on sale, then that is always bannable.
To the OP on whether it's legal, then no it's not. But realistically you're not likely to be taken to court over it if you were to get caught. That doesn't make it right though.
As for if it's justifiable, that's up to personal opinion. The game isn't for sale online anymore so pirating the digital version is all you can do. However, there still exist hard-copy versions of the game which you'll probably find on sites like eBay or Amazon, or even in game shops. I have a triple copy of FO1/2/Tactics which was purchased in a shop.
And I suppose you'd have to consider your own morals too if you were to go ahead.
