Cause he's the most popular X-man. There's a reason there are no solo cyclops games or movies.
This is what ultimately destroyed X-men in the long run. Logan is awesome but the X-men are so much more than just "Wolverine and some other guys".
They demystified Wolverine by overusing him too much. Keeping him as a side character added a lot more to his mystery and his whole swag. Old school writers knew that the little hints about his backstory and actions were more interesting than anything they could have actually given us.
For example, you didn't even need to see what Logan did to his enemies most of the time, you just KNEW they got murked.
The Dark Phoenix Saga was legendary because that was one of the RARE times we actually saw Logan going off. Scenes like that were memorable because we didn't get them often. Logan used to have that Rogue One Darth Vader aura.
The whole point of Wolverine is that he's a loose cannon, which gets everyone in trouble just as often as it saves them. He's the wild card, so you need more rational characters (Cyclops, Storm, Professor X, etc.) to balance him out.
But since you mentioned Scott, he's a more legit character than people think. A lot of cats write him off because they only know him as the guy who got punched for leaving Morph in the cartoon, when his character has always been deeper than that.
Most of the X-men besides Wolverine were never pushed as solo characters like that. The X-men are different from the Avengers since almost all of them were designed to be a part of a group from the jump instead of existing as their own characters with their own rogues galleries like the Avengers.
Plus, Cyclops has BEEN making Wolverine look stupid since the 70s.
Jim Shooter era Marvel (1979-86) >>>>