The most obvious reason why every Duke and Harry can run an IEO on P2PB2B is that they have free listing opportunities for projects. The project only needs to meet with some conditions which are not stringent. Some projects use both P2PB2B and other exchange for their tokensales and that's a bit understandable, but for those projects that use only P2PB2B for tokensales, I advise you don't waste your funds.
I think it's best not to waste time at this exchange as it will certainly only disappoint you more because in fact the exchange has never been trusted. All IEO projects at p2pb2b are garbage and will definitely only cost you money. In addition to p2pb2b, there are exchanges such as VinDax, Latoken because these are also two exchanges with many very bad IEO projects and are not encouraged to participate.