I dunno - I can't bring myself to dislike it. It seems to me that it is more helpful for guests than all subcategories showing as 5 stars, but with a lower overall score like (randomly) 4.93. As hosts, we're far more familiar with the system, so we realize that the "big" review number reflects the overall category, but guests don't, so many have likely wondered why, if everything below shows as 5 star, the "big" number is lower.
I suppose this approach could also help the many hosts who get 5 stars in all subcategories, but only a 4 star for overall. As a guest, if I saw a rating at (say) 4.80, but all the subcategories were 4.9s or 5s, I'd feel better about booking the listing.
@Susan151, at least your browser shows the "sliders" clearly. Mine (Firefox) seems to have issues with this layout and shows the "sliders" overlapping the numbers, so I can't make out if I'm looking at a 4.6 or a 4.0 on some of my competitor's listings ('cause I'm snoopy like that).