It's more of a problem with the guys GSP's been fighting than GSP himself.
Everyone he's fought has been severely flawed in one large area where GSP is well rounded and can exploit it.
Dating back to his title win
Matt Serra(it's literally Matt Serra)
Jon Fitch (poor striker, shaky defense....one dimensional top control grappler.....beaten up standing and worn down with occasional takedowns)
BJ Penn (grease aside, BJ is a LW who's done poorly at WW which is arguably 25bs heavier than his optimal weight class)
Thiago Alves (very one dimensional...poor defensive wrestling and poor grappling in general....wrestled to death)
Dan Hardy (laughable title contender...poor in most areas...average in striking)
Josh Koscheck(one dimensional wrestler who thinks hes the second coming of Chuck Liddell. Poor striker. Poor fight IQ.
Average jiu-jitsu. Jabbed to death while overusing overhand rights and not trying to wrestle despite ability to take GSP down)
Jake Shields (Average to poor wrestler with abysmal striking. Outstruck in boring point fight)
Carlos Condit (Best guy all around GSP has fought but severely lacking in defensive wrestling.)
Nick Diaz (Poor fight IQ...limited striker....poor defensive wrestling)
IMO Hendricks will be his most interesting challenger since he can strike and wrestle. His submission grappling isnt very good but he can scramble a bit so it's good enough. He just needs to control GSP anyway...not submit him.
Oh and the main point of this post is that I don't believe GSP "plays it safe". I believe he's not that great at any particular area in MMA. He's very good at everything. GSP was never the best wrestler in MMA...that was an extremely distorted half truth. He has the best takedown setups in MMA because he's explosive and because he sets it up so well with his strikes....he has outstanding balance and reactions so he can defend most takedowns for the most part...
But he doesn't hit particularly hard...and he doesn't have great submission acumen....so he doesn't finish fights.