First and foremost bucket shop brokers are fake broker sites. So you can't pass a fake one as legit one. In short we can't consider them a forex broker sites at all as they are fake and their rules and reason are nuisance as its a con broker site to start with. A legit broker site has legit reason why its does not allow scalping.
I totally agree with that , my point it is that these "brokers" often claim that they are legit. In fact I skip brokers which doesn't allows scalping, even though its not my trading style.