Why are non-folding tyres still manufactured? Folding tyres are easier to mount and store. They are also a gram lighter.
Why are non-folding tyres still manufactured?
Why folding and non-folding tyres of the same model differ in price more than a few cents, which I think the price difference between 2 meters of kevlar cord and 2 meters of steel wire would be?
The reason non-folding tires are manufactured is that people still buy non-folding tires. Companies will make what sells.
In the original post there is a comparison between two tires of the same model, one is folding and one is not. According to the post:

folding and non-folding tyres of the same model differ in price more than a few cents.

The question asked in the original post is really:
Why would someone choose a non-folding tire over a folding tire if the two tires are the same model and virtually the same price?
Someone would choose a non-folding tire over a folding tire of the same model and price is if they didn't need the ability to fold the tire and they felt that a non-folding tire is easier to install.