At this time, the X-Men had a major success with their "Age Of Apocalypse" storyline featuring an alternate world in which Professor X died and Magneto founded the X-Men in his memory. This storyline was highlighted by the entire X-Family "restarting" their respective series with a new name (they returned to normal after four months).
The powers-that-were decided that the same thing should be done with Spider- Man. At this point in Spider-Man history the spider-clone was proven to be the original Spider-Man (as of Spectacular Spider-Man #226. Following their marching orders, the creators applied the "strange new world" concept to the Ben Reilly character and thus the "Scarlet Spider" titles were created.