So you expect people to work for free on what you think is important, rather than on what they think is important?
A different analogy: I invite you over to a BBQ that I'm throwing. You show up and say you don't want to eat what I'm preparing. You don't want to bring anything or contribute because you can't cook, and I invited you, so it's rude to ask you to contribute and now I owe you food that you want that I'm not interested in making.
You don't want a "community", you want to be provided with high quality low cost software.
Even in your sandbox example: if I'm building a sand castle you don't get to demand I build it the way you want just because I said you could play too. I don't want to build that into the castle. If you want to add that bit, you can do it. I'm sharing by letting you play in my sandbox and that doesn't entitle you to dictate how I play in the sandbox. We can play together, but that doesn't mean I have to do what you want.
Remember that what you're doing under the auspices of "community" is justifying telling other people how they should give you free stuff that takes a lot of work that they don't want to do unpaid in their free time.