Everyone responding so far has made prefectly valid points, and I agree/subscribe to most of them.  I know, from my previous marriage, that it IS an important factor in the relationship, just as several of you have mentioned already, like any other facet of the physical portion of the relationship. It's part of who you are, and needs to be part of your intimate time together. So, while some may argue that the eyes of love can look past a minor flaw like not sharing one's passion for tickling, I can honestly say that, having "been there, done that", that's not true. At least for me. This is who I am. Love all of me. Period. I was married to one of the most ticklish women on the planet for 13 years, and she made no bones about the fact that she not only hated it, but that it wasn't even to be tolerated. (WTF was he thinking! , I can here some of you saying, LoL) If you're not getting what you need from your spouse, then what are you, other than roommates?
That's why she's my EX  wife.  For a long time, I stuck it out, even knowing that our relationship was steadily growing unhealthy.  I consoled myself with platitudes like "I was raised better than to run away from it, Mom & Dad made it the distance, so you can too." and "You either make your son the child of divorced parents, or stick it out in this lousy marriage...  it's a lose-lose proposition either way ya look at it, and this is MUCH easier than going through with divorce, just live with it."
Feh.
Thank God I woke up and got paroled from that life sentence!  I almost immediately discovered the community afterwards, and found out that I'm not alone in this thing of ours.  Transitions are scary and can be hard, but quite often are the best thing in the world to do once you get past them and move on.  Gives ya wings.  You never really know how bad you feel until you don't anymore.  I was fortunate, though, and I know this...  most people stick it out until it's gotten so unhealthy, the relationship is actively hostile.  I had a good split, and I'm SOOOOOOOOO thankful for it.