Man, does this thread ever bring back memories for me...
Ya see, it was way back in second edition, the game had only two players and both of us were thieves. The other player's character had this cloak that gave him the ability to fly, so he never put any skill points into climb walls. On the other hand, my character concept was to be the ultimate intruder, someone who could break into anywhere, so I maxed out climb shortly after HS/MS.
Despite the fact that my character was alot cooler than his,

I was always living in his shadow, so to speak. He was always a few levels higher than me because I joined the campaign much later than him, his EQ was leagues ahead of mine, and to top it off he was playing some seriously broken kit that gave him a bunch of fighter abilities with only trivial penalties to his thief abilities. I didn't really mind so much because I was playing the character I wanted to play, and I was having a good time. Or so I thought...
Then one day he turned stag on my character and our organization. I had the singular pleasure of hunting him down and having him killed (he seriously outclassed me, remember

). The man that killed him took all of his wonderful, wonderful EQ (including that cloak) except for his signature weapon, and a ring which I took for my troubles.

Because my character still felt some degree of loyalty to the guy, she decided to spare him and get him raised, minus all memory of his betrayal and the events leading up to it (there were what might be considered "extenuating circumstances" for his actions). Things mostly went back to normal after that, and we went back to our regular routine of infiltration and assassination. However, our first mission together afterwards, had us climbing into a second story window. This was something my character could do in her sleep, but the other character, bereft of magical items, had only his base score for being a thief and his bonus from dex.
Watching him struggle round after round to make a 15' climb was better than watching him get killed. I felt truly vindicated.
And that's why you should spend skill points on climb: people who actually roleplay will someday have the opportunity to laugh at you.