SC lost practicality when Alliance based play became the norm. The only way to make it relevant for Alliances is to artificially increase the significance of it or to make it better designed.

If SCs are required for proc systems or drops or clearing content, then that would be a way you could make them significant but not actually more relevant to game. I don't like proc systems. They feel like a cop out. Instead of fixing the already very broken hate system, they distracted us with spamming random JAs, spells, and WSs for no actual purpose.

If they wanted to make it better designed, then they could do a number of things to make it relevant for game play. SC damage is largely useless against terrible things that have extreme amounts of magic resistance. That really should be addressed in some way. They don't have to make it so SCs do obscene amounts of damage, but it is ridiculous that you can do Light on something for 1/8 of the closing WS damage. That's just bad and makes people see the obvious weakness in an otherwise fun system.

They could adjust it so that you could toggle SCing on a party level or an alliance level. That way, you put all your corresponding WSs in different parties so they don't cross the streams.