He really didn't look that good in that match at all. He won by a fast-count and then tapped out to Sting's finisher. Starrcade 97 may be the most blown out of proportion event in wrestling history. WCW was perfectly fine afterwards, they didn't lose massive ratings or members of their fanbase, WCW continued going on very strong until around 1999.
And once he leaves the main event, the ratings plummet.
A five minute squash? That would've been even worse.
Hogan did not kill WCW in any shape, way, or form. He had absolutely ZERO to do with the inner workings of the company, it's finances, or anything remotely important other than he had creative control over his character.
Hogan didn't kill WCW. The only person that killed WCW was Vince McMahon.