Agreed, as I understand it - & I'm not a tech guy - core wants to keep the spam in a certain area (op_return) to keep it away from the utxo area. At least, that's the official argument. But you can't say with certainty that this works. Also, the argument of the other side seems conclusive to me that a filter (unlike censorship) does not have to filter 100% to be legitimate. The fact that core tried to rush the whole thing through by removing the option for any “core mempool” altogether has, in my opinion (post above), quite rightly caused an outcry. I see it as a test of whether non-tech bitcoiners really think for themselves or are just following another “pied piper”. Since bitcoin is such a unique one-shot, even this painstaking dicing out of little things isn't a bad thing. Many are deepening their knowledge & we can all find out how this should work if so many people want to participate as Self-responsible as possible. However, it looks like Core has now considered another proposal in which the option remains. Then you don't have to decide right away :)