the problem with this exchange comes down to the fact that the main requirement is the listing fee they don't get stuck with the project or with what they have to offer with the simple gain of them to earn some money
Listing fee can be cheaper on these exchanges but that's not the real problem here, the problem is the team of exmarket and other exchanges like it, they don't pick projects that are good, they allow any projects on their exchanges unless you can't pay for the listing, they hardly turn project listing down that's why exmarket, latoken, p2pb2b and others are the best place for shit and scam projects
Indeed, as long as you can pay for the listing fee then you're fine with the exchange. But choosing a not reputable exchange for your project is like letting itself to fail, yes the listing fee for big and reputed exchange is high but in return your project is likely to succeed and gain wide investors. So it depends on the dev, if they will push through their project to progress and be on top they will choose first a good exchange for their project.