Simply put, he could do the business for the band, and for the Kiss brand. So, while the original hiring might have partly been a business decision, Thayer is a lot more than just a hired gun,.
Love 'em or hate 'em, Kiss is one of the biggest grossing, most popular Rock bands of all time. If success is pleasing your audience, Kiss scores every time. GI's Stuart Bull meets the band's lead guitarist, Tommy Thayer, while Kiss fan William Black, fills in the background story.
I always tell people that want to make it in music be prepared to work hard for a long time to make things happen. There are no short-cuts. There's no rules. Effort = Success. Good luck!