There is no way in hell they can write any coherent argumentative essay on Thomas Theorem, Social Construction of Reality, division of labor, serotonin and whatnot.
You're right there old English, except that some of them still meet the requirement somehow, showing you that when I say 'level', it isn't only the language. When you look at it, it's an amazing mix, because the best essay writing sites are also run by non-English speaker. If you spend some time reading that site www.essayscam.org/Forum, you'll come to know who own those sites, where all students are flocking to part with their money, because it's more or less a controlled industry. Probably, if you search for "essay writing companies" all the sites you'll find can lead you to two or three companies run by non-native speakers. The hot button had been having a knack to come up with attractive and believable sites and the rest is money-making, hard work, and anxiety since there're dry seasonal spells too. It isn't different from the dot-com mania, since these owners are also young people from everywhere, with some smarts they acquired when they were students, because they were using such services run by decent folks from North America and the UK. When they finished their school, mostly in Western universities and colleges, they went into business for themselves. They know what it means to be non-native speaker, the reason why they are serving that population, from the bottom of their heart. Like I said it earlier, they also put up with native speakers, because they still can trap not knowing native speaking clients that could demanding about the end product they are getting. So there you have it, it'll always remain to be a vicious circle. I am not acrimonious about anything, except that for native speakers, the pie is much smaller at around 20%.