A Round Hole Into a Square Peg?

So I'm watching "Hidden Potential" on HGTV where they're showing a young couple with a 2-year old daughter three houses with ideas for renovating into an "open" floor plan. Second house is a lovely Colonial built in 1790s and selling for $399K because it's so "old". And the designer has ideas for changing the entire floor plan into a modern style, possibly knocking down walls? What. an. idiot. Desecrating a well-kept, old house with history should be a felony crime.