Some thoughts:
1. It's very disappointing when your child doesn't like to do your favorite things, but it happens. I spent a lot of money on a beautiful bicycle for my daughter, only to have her end up saying, "I hate bicycling." I no longer spend big bucks, hoping that my kids will share my passions.

2. My kids do like kayaking, but not as much as me. They like to paddle short distances every once in awhile. They don't care to learn how to do self-rescues with a paddle float, or learn to roll. In short, their first preference is for a sit-on-top.

3. They aren't careful. They bang their kayaks into other people's. They drag them across rocks.

I bought an Ocean Kayaks Poco. It's shaped like their Scrambler, but shorter, and it has a molded-in back support (plus a cupholder that's perfect for soda cans. My kids like this.) It didn't cost much. It's indestructable. They can climb back in after they fall off. It will be easy to sell when they outgrow it. (They almost have already.)

I think I've learned my lesson from the bicycle. I'm not pushing them to kayak. I'm not saying "What a waste! I spent all that money on that kayak and you NEVER use it." Instead I'm letting them go only when the really want. If they only use the Poco a few times, that's okay. Hopefully, using this approach, I won't turn them off to kayaking, and when they get older (and WISER!) they'll learn to love it and share my passion, and we can paddle off into many adventures together.