By giving the users choice in the setting for the nightfall it makes the game more enjoyable. Modifiers can still be randomized to create challenges for "favorite" strikes. Playstation users can enjoy their exclusive strikes as possible nightfalls, non-DLC users won't be locked out of content.
Bungie can still incentivise players to play certain strikes in other ways, such as bonus XP, or by making loot drops unique for each strike.
I'd like to see this apply to the weekly strikes and dailies also. With respect to dailies, incentivise players with material drops by doing a story mission on a particular planet.