So we are promoting the exchanges to police, judge, jury and correctional institutions now?
Exchanges list coins in good faith, its is the communities, miners and traders that decide on how this will go. Any coin with good community, good development and sound concepts can archive success.
Say i have my money in a bank, the bank director doesn't like me or the way i do business. Does he then have any claim to take my money? As long as the rules are followed exchanges can't do anything.
I personally agree that multipools are frustrating, counterproductive and a cancer on the crypto community but you are barking up the wrong tree sorry!
Lets not pretend that because cryptocurrency has no "laws", that we can also set aside morality too. As you, and many others would agree, these multipools are having nothing but a negative effect on any pottential coins growth. Whether they kill it alltogether (which has happened to others) or just stunt it, its a negative effect.
A bank can refuse to accept a customers business, a bar can refuse to serve, everyone has the right to refuse service, even exchanges.
Individual miners or mining pools have zero power what so ever to stop this. Developers could choose to implement gravity wells/quick difficulty retargetting, but ultimately the process of a huge pool vastly skewing the figures and then dumping in the market is counterproductive to the entire microeconomy of an individual coin. The fact they play whack a mole with the whole range makes it even harder for any coin to become successful in its own right. Thats why they all blend into one great big cloud of coins affectionatley termed "shitcoins" by many.
The only block between these multipools and them cashing out their gains, leaving a trail of high difficulty and low values, is the exchanges. If an exchange took a stand and declared it would take any and all necessary actions to prevent multipools from trading there, many miners would go to it as an exchange of choice becasue they would feel somehow protected against the dumps.
As you say it is in the power of the community rid themselves of these multipools, but there is only so much that a single miner can do.
If you do what you have always done, you will get what you have always got. If you dont do it, you will never know what would have happened if you did do it. Its fairly simple to post a warning that any deposist from multipools will be held, and returned if confirmed that they came from a multipool. A simple warning may be enough to disuade them, but unless somebody tries, we will never know.