It's branding. Simple as that, it's branding.
If the idea of another title that used similar themes and concepts was deemed profitable then they would market it under a variation of the norm (adjectives; Ultimate, Amazing, Scarlet). This is done to denote what aspects of the brand you are marketing and makes it easier when identifying your product. Miles and Miguel are both spider-man but use different adjectives when it comes to branding. They have slight variations but are for all intents and purposes are spider-man and this hasn't affected the main books sales. What is exactly lost with Miles being spider-man?