1st reason - very silly jokes, belly laughs, slap stick for all ages
2nd reason - food is like you are on a picnic. Nothing fancy. Kids seem to like it fine, so do adults. The HDD will accomodate special diets - no salt, veggie platter, no sugar, pizza or PB&J for kids. Just call HDD (dining #) 24 hours in advance (also have them note it on your PS) with your food requests.
3rd reason - cost is worth it. Plan 2 'cheapie' lunches. Do breakfast in your room 3 times (food you brought with your or bought at the food shop stop on your way to WDW). Then splurge on the HDD.
4th reason- even the kid or adult who says they will not laugh - will at the HDD. My DS at 9 said he would just sit though it politely. Not only was he polite - but had the biggest smile and laugh at WDW. He even won a glass boot from our waitress for stacking up a plate full of cleaned-off rib bones.
5th reason - The boat ride from MK to FW is fun. Spend the afternoon at MK and then take the boat to the camp ground.
From the FW marina it is a very short walk (3 mins) to the HDD building.
6th reason - after the HDD, follow the crowd to the bus stop.
There will be a bus right back to your resort or DTD.
7th reason - You may see your spouse or child up on stage. HDD also acknowledges birthdays and anniversaries. Bring your camera. Pictures of the show are permitted.
8th reason - Your waitress/waiter has a dance at the end of the show before they bring you your strawberry short cake.
9th reason - It's fun

Remember to make your PS early. Up to two years in advance. Best seats are on the main floor. But all seats are good.
The earlier you request a PS, then more likely you are to be on the main floor.