It’s multiple factors.
The gay sucking up is a big one. It’s just not family friendly no matter how it’s packaged. Turns off a huge amount of people that have many, many other comparable shopping options.
Second are the stores themselves. Many look old on the outside and inside. The majority are not renovated. It leads to upredictable shopping experiences, as ads give expectations the actual crummy old unremodeled store, doesn’t.
The whole store in a store concept can’t really catch on when the majority of stores aren’t yet set up this way.
Further their normal shoppers are not used to thinking of JCPenney as more of an “Amazon” type place bringing under its roof separate vendor stores.
It’s just a hodgepodge mess.
Over the holidays, I went in one not far from their headquarters - not the closest; perhaps second closest. Saw some stuff on display in the aisles that I wanted to check out for my wife. Couldn’t find the actual product. So signs as to where it might be located, and I couldn’t find it on any of the nearby racks. Left empty handed.