Horace!? Royce.
Fighters aren't involved in the business side of things. That job belongs to promoters and organizations. I understand and agree with what you're saying but you need to understand more fighters care about their records/legacy more so than entertaining fans.
Not to mention sometimes fighters have bad nights. It happens. GSP always tries to finish fights. Sometimes it just doesn't happen. Anderson Silva fights best when he's fighting an opponent who wants to fight and brings it to Silva. He is a counter puncher remember. Penn finished his last 5 opponents at LW. Silva has finished 8 opponents out of 11 fights in the UFC.
And as far as GSP, the only opponents he hasn't finished in the UFC are:
Karo Parisyan - Before the GSP fight in 2004 had never been Subbed and only had one TKO loss (Corner threw in the Towel) back in 2001.
Jason Miller - Before the GSP fight in 2005 had never been KO'ed and was Subbed only once back in 2002.
Josh Koscheck - Before the GSP fight in 2007 had never been KO'ed and was Subbed only once back in 2005.
Jon Fitch - Before the GSP fight in 2008 Had only lost once by TKO and once by Sub, both back in 2002.
Thiago Alves - Before the GSP fight in 2009 had only been TKO'ed once (2006) and had only been subbed 3 times in his career. The last time being back in 2005.
Dan Hardy - Before the GSP fight in 2010 had never been KO'ed and had only been subbed 3 times in his career. The last time being back in 2005.
In other words, there's no shame in NOT being able to stop those guys because NONE of them up to the point that they fought GSP were known for being easy guys to stop. Mostly decisions losses. And the subs/TKO's they had were years earlier.