I took some quick measurements. The previous version leaves 2% of my browser window as whitespace containing no images or text. By comparison, the new version is 53% whitespace. That seems pretty extreme to me.
There's a reason we have a character limit per line when writing code - it's much easier to read and understand short chunks of vertical text. Personally, I find it far more comfortable reading text which doesn't go above 600-900px in width and this has been a well known UX/UI guideline for the last 10 years. Having your eyes go from the far left to the far right of your screen is also very straining on any >21" screen.
But the real question is, why is it good to strain the eyes darting them across distances that large. What is gained by filling in the white space just to fill it?