Because Freedom.
Remain anomymous, anything goes, pump as you please and none shall interfere.
I personally prefer
the unregulated exchanges to the regulated ones....but the compliant exchanges have all the volume now because pussies like you are too scared to live in the 2012 world of Bitcoin, which was an Anarcho-Capitalist paradise
believe me, in the end, there is no difference between them, the only one difference is that "word", regulated, the rest is the same, they will scam you if needed, but with only one difference, the regulated one, will scam you using the law, so if people feel more comfortable with it...

this is another good example about why decentralized exchanges should be used...