Why is this stupid? The api is written for a more personalized trading and not for laming down exchanges...
yes, but in that case there must be an api response like {"Error:You're Banned"} or some kind of advice for the user.
An html page can't be a response for an API System.
Usually HTLM page means "Site maintenance"
From my point of view this is an error on Poloniex side. In fact, very few people are effected.