These rules are intended and introduced to protect consumers from fraud and help them if they make an honest mistake. They are not intended for people who can't make their mind up. The system is already abused, and companies are fighting back by blacklisting customers. People who think they are oh-so-clever by regularly ordering a bunch of wares, and sending them back, find themselves no longer serviced. Especially if they use the goods for a week or so, e.g. wearing clothes or using a huge TV to watch a particular sports event, and then sending them back.
Companies use the same mechanisms and agencies to share information about bad customers they use for credit rating. If you cost a company money they no longer want you as a customer. It is that simple.
It is not even only EU sellers blacklisting customers. A lot of Chinese sellers just don't serve several countries any more. Some, because shipping is expensive or unreliable, some because customs is a PITA, but also some because the buyers regularly go on their tits.