Yes, I took my then 2.5yo DD along with her three older brothers. All the kids get treats before the cruise, a small "prize" (older kids answer trivia questions to win their prize, but she was just handed one), and, if they like, the chance to meet a couple of characters. I actually think sitting on a boat with a lower noise level and no crowd pressing around you is a better way to view the fireworks with kids who might not love them. Being on the water is a lovely way to see the Electrical Light Parade, too.
And while you have to pay for yourselves and any older kids, anyone under 36 months is free.
But every kid is different. YMMV