Your misinformation is as bad as your grammar. Poly strings weren't available in the 80's. Technology for that wasn't present. Do you also believe LEDs were available in that period, but people just never "liked" it and that's why it never caught on?
How about this, if you make a false statement, don't phrase it in a way where it sounds factual, then people who don't know better will start assuming its factual and the greater amount of people who think something is fact creates the bigger illusion the lie is real.
Poly technology wasn't developed for tennis back in the 80's. not even sure it was developed period for other processes/use ages for other things.