No offence to Nigeria or Nigerians, but why is it that there are so many transactions involving folks from this country on Paxful?
No offense taken, sadly that's a reputation we gave ourselves. To make you understand why there are so many transaction involving Nigerians on paxful, (just as @Ailmand said, paxful works like localbitcoin making it an alternative which was more accessible) meaning you can easily trade peer2peer without involving third party which lead many Nigeria into using their service as centralized exchanges that one could easily trade his/her coins into our local currency naira wasn't available we all turned to P2P platform for that exchange to be made possible. Although now we have exchanges like LUNO that offers those feature but majority of individuals still uses localbitcoin or paxful.
Also another factor that increase our transaction number on those P2P site was when the government started showing strong negative signals towards the usage of cryptocurrency in the country. In some case if your bank record has any cryptocurrency related transaction your account get seize or closed. But with the use of P2P platform you could easily avoid the government tracking your bank records and linking it with cryptocurrency related transaction.
Now this were the geniue factor that contributed to the increase of users using those P2P exchange before scammers saw an opportunity to capitalize on the trust feature of those platform. You should understand though not every one on those platform that posses as Nigerians are Nigerians some of them are our neighboring country. The whole scam issue is an African problem but they use Nigeria as their country since the bad eggs have spoiled the country's reputation.
Trading of bitcoin is the number one and biggest use of bitcoin in Nigeria (Africa as a whole) whether it's genuine or fraudulent related that's why the number of transaction are high. Did a post on that something ago titled;
Uses of bitcoin in Africa 
