The only blanket statement is, there are no blanket statements.
Just because one dealer does these things does not mean that it is the same across the board.
Just because one dealer does not include these items does not mean it's time to walk away.
What if, that dealer is selling you the trailer for $5000 less than anywhere else, because they cut out the overhead of including "freebies" with their campers? You do realize that these "free" things are not really free, right? They're working it into the price of the trailer.
If you can go out and but those things for yourself and still have a better deal than the dealer who includes all these things "free," you would be pretty silly to not take the deal. However there are some people who hear the word "free" and lose all common sense. That's what these dealers offering freebies are counting on.