I would suggest to the same way that ‘anyone’ is to ‘any’, ‘each one can be to…each’, so the following constructions probably provide the most succinct way of saying that you want a response giving objections against each person: What are each

one’s objections? What are the objections for each one?

‘Each’ can be a pronoun as well as an adjective or an adverb, but it doesn’t have a possessive form, even though ‘each’s’ is permissible according to standard English grammar – in the same way that you can create a past participle out of a verb ifinitive by ‘-ed’, as a weak verb, until there is a strong verb alternative. As there is no strong alternative for ‘each’, there’s nothing stopping you putting an apostrophe’s’ after ‘each’ to create a possessive form. Except for it sounding awkward because it is not a form one hears in practice. What happens if a grammar zealot stops a language from evolving from the unofficial to the actual language?

Is there any way to explain why just so many people are complaining about it?