Yosemite National Park gets a .5 rating is beyond me ken
Anyone that puts .5 for Yosemite I feel bad for. Because, the assumption must ultimately rest on a poor experience. Which ALL of us have had at one point or another. Perhaps, a busy weekend or holiday and getting into traffic in Yosemite Valley. Fully-booked campgrounds, gov't shutdowns, wildfires, and/or wildlife behavior adapted to humans? There are several conditions that could contribute to a poor visit. Yet, this is where its difficult to be objective as we can only judge a WHS based on our own experience, weather and tourist numbers included!
As someone who loves Yosemite and have visited many of its wonders, I'm dubious of any visit being seen as a "full Yosemite experience" that does not include Glacier Point or the backcountry. Sure, still a WHS tick, but perhaps equivalent to visiting Paris for a day just to see the Eiffel Tower and leaving before dinner. Sadly, popularity is an issue for Yosemite. I would agree that Yosemite Valley is far too busy during Summer weekends and holidays. Another sad reality for years, was an enjoyable visit to Mariposa Grove was often hampered by visitor numbers and a degraded environement.
There is hope still however, as return visits often provide a more positive experience with greater planning and tough lessons learned! This was the case for me with return visits to the Grand Canyon, Macao, and Namhansanseong.