As I said solutions to this are being worked on. It's not a huge issue in my eyes, even reddit limits how much new accounts can post until they get a certain amount of karma and for them it barely costs anything to store data while they also archive it every 6 months.
There are many projects that offer free delegations such as gift.giver and others who do it manually to people they notice are "legit", i.e. not bots or attempts at abusing the HP for free curation rewards.
In the near future people will be able to delegate RC directly instead of HP and many will be more inclined to just throw it out at random as there's no abuse factor, aside from just spamming the chain for no reason other than to fill it up. No monetary incentive the way that exists now tho so a lot of abuse will go away while genuine users will have an easier time finding delegations to use Hive as much as they'd want.