Dream Land is in a really awkward position where it's clearly an inoffensive stage (anyone who seriously complains about Whispy Woods is, IMO, a stick in the mud) but, small differences aside, it's honestly not too different from Battlefield.
An anecdote: This past weekend I was at a smallish local (36 entrants) where the starter list was BF/FD/SV/T&C/DL. Every single match I had, my opponent struck one of Battlefield or Dream Land, but never both. When I struck last, I picked the other; when I struck first, I eliminated FD/SV and from there it was basically a tossup.
Let's not kid ourselves: Some characters benefit from Battlefield's arrangement more than others. Some of these characters could even use the help from having multiple such stages in a list, such as Robin. But others don't need it, like Rosalina or ZSS. (I'm making a bit of an assumption that ZSS likes Battlefield, but given her juggle game it makes intuitive sense at least.) And every time I took advantage of the fact that the two are mostly (not entirely, but mostly) interchangeable, I felt just a little bit bad that I was abusing this fact. Not enough to stop me from doing it, but just a little.