I've never had a problem with box builds, Not only does it remind me of the early days of blockland it's also what most houses actually look like.
It's true that most houses are square in shape, but generally I find it ugly if they're perfectly square and on their own as in a fully detatched house.
If it's a line of square houses attatched then that's fine, but generally for me if it's a house not attatched to anything I'd like it to have some extra shape.
Whether that's a corner in the design or making it rectangular or even adding on a garage that sticks out. All make them seem slightly less basic. Or rather, cleaner looking.
But then again I suppose a box house has the means to be good if it has extra details to it.
Good windows, good roofing, good colour scheme, a good brick formation in the walls. Any protrusions, like chimney's or small balconey's or porch covers.
A garage or shed or garden are also good at making them work well.