We have seen people want to the pirate king, people strong like luffy or weak like buggy.
Roger created a dream because of all of his actions and he left a big impact to the world, so many, many people start dreaming becoming the PK.
But do we ever seen people that want to become the WSM or the WSC?
Those titles are given by people (oda) in order for the readers to realize the magnitude of a character's power.
The thing with Zoro's dream and what makes it so unique, especially as the story is progressing is that a boy (zoro) having a dream about disciplines, training, hurting etc in order to be the strongest of those who call themselves swordsman. There is no shortcut in this and while PK is a harder achieving dream there are shortcuts.
I seriously don't get it how wano help's haters with this argument.
Wano is an enslavement country for the last 20 years plus we haven't meat someone in that age who could be called strong let alone a wss candidate.
After we have seen that shanks was Mihawk's rival, Roger being a swordsman and Mihawk being the second known person in hundred years to have a black blade, arguments like this are kinda silly.