Outdoor Kitchen

I think its just a personal preference for most folks. If anything else was going to be a determining factor it could be how/where you camp. If you are usually in an established campground, with electric and a picnic table at the site, many choose to cook at the table for convenience. Some who boondock or remote camp may look at the outside kitchen as a means of not putting the additional heat from the stove in their RV.
It's all up to how you want to use your rig.

I love mine. I never cook inside unless the weather dictates it. The fridge is great for all my drinks, freeing up space in the inside fridge. The sink, with hot/cold water is extremely useful.

It is a must have for us. We never cook inside unless the weather is really bad. Love having a fridge outside for beverages and the sink is handy. Last two trailers had one.

Yup, your call. Like Donn I carry a gas grill and Coleman stove.

I think it's entirely up to you and how you feel about cooking outside. We bought a 5th wheel so we wouldn't have to cook outside any longer. We can grill if we wish, but an outdoor kitchen is something we would have no use for.

Worth it? Its up to you. Personally I find it much less wasted space to carry a good quality gas grill and a Coleman gas stove. When we go camp hosting both get setup on the table and they stay there all summer. Works great for us.