Imo it's more down to the execution of the concept, shooters that are competitive generally are about racking up kill as a core component regardless of mode, Splatoon however turns this on its head, anyone can fire a weapon in a shooter but not everyone can do it well enough to be good.
Splatoon's competitiveness doesn't require a player to be some Counter Strike level head shot specialists or to get kills to have an influence on a match which is why it appeals to people who don't normally like shooters.







