If they're not shitcoins then they wont be harmed by any attempted attacks, so where's the problem?
if she floats, she's a witch.
They'll all get attacked sooner or later. If they're going to fold up & die to some simple attack then it's better that it happens before anybody gets tricked into putting any money in. It's just testing their security. If they sink they're a witch, so it's fair, you see? You wouldn't want to put your money in a currency that's so vulnrable to attack that just a few people can take it down with little effort, would you?
If it's not a shitcoin, then it's just a little harmless stress testing on the network to allow the developers to see if their defences are adequate or if they could be improved.
Before I start my shitcoin I'm going to invite people to attack it. Come on you fascists if you think you're hard enough attitude.