Has the apple itself changed? I don't remember the modern frustration with mealy red delicious apples when I was a kid - I loved them back then. Is modern shipping or farming rougher now?
Noting the 1980s as when it all started to go down hill: "But as genes for beauty were favored over those for taste, the skins grew tough and bitter around mushy, sugar-soaked flesh."
They're all propagated from cuttings, hence they are genetically identical. Which means the skins are the same as they were before, and the flesh as is bitter (or otherwise) as it was before, etc.
If they weren't, they wouldn't be called the same name, as evinced by many other 'modern' varieties, that are crosses or hybrids of (other) known apple varieties.
No, it actually doesn't mean that. First, genetics aren't the only determinants of those features; environmental factors, growing, shipping, and storage conditions, etc., all play a role.
Second, propagation by cutting doesn't mean they are genetically identical, because mutations still occur and are an important source of variability, and not all of them result in different branding.