why this coin hase only 1 exchange (polonix) is this scam

People lose millions because of bad 'investments'.
Follow common sense and don't invest in crypto. The risks are extremely high and rewards NaN.
I stopped mining PASC a long time ago. It was not profitable at all (with 6 1080tis) since early 2017.
When the hardware breaks and you realize that you were mining so that someone lucky can buy 500,000 PASC at a time at the expense of your time and real money...
The story has it that ASICs were silently mining ETH, XMR, and ZCash for a long time. Yes, there are not ASIC resistant after all.
It's a matter of time before Bitmain silently mines with 10000s of those machines. One can do hashrates that would require massive GPU resources.
You see how that doesn't make sense, right?
That's why there are HFs, but by that time it's a bit too late.
Look it up. Baikal Giant B has been mining PASC at 40GH/s for 4 months now at 200 watts power usage. One 1080ti can do 1.7GH/s max.
Simple math.
PIP-0009 is not implemented yet and even after I don't see how CPU mining can undo the damage (it's impossible that it will be profitable or worth the effort in any way and I did read that document that explains randomhash).
I know this is a long post, but this goes back to the 'investors' that buy PASC.