>>6328486>and the cost in terms of components shouldn't be that bigYou need to realize that Lego doesn't manufacture pieces unless they have to. It's easy to make an amazing build in LDD, but Lego only has so many different pieces in production, and those are being produced in only so many different colors.
If the initial design calls for yellow hoses, but TLG is only producing hoses in black, then the final product will have black hoses. If the initial design uses pieces that TLG hasn't produced in a decade or more, the final design will use different pieces. If the initial design uses connections that TLG doesn't consider to be stable enough, the final design will use a different setup for connections.
And as the other anon said, there's a cost analysis that goes into production as well. This is why the 10,000 piece Ideas sets never get approved, even if they get enough votes.