Not only in Gridcoin, but nobody in blockchain sphere found a solution to what you (and many others) desire - 1 wallet 1 stake does not solve anything, as whale can create hundreds of separate wallets. You would have to tie a person to the wallet, take passport scans etc and validate. Still someone could use stolen identities or buy identities from homeless etc and play the system.
Most of daily rewards is going towards research and to sign up to the pool and receive rewards you not need any GRC. Little owners are somewhat covered. Now they can also spend a dollar a day to reach a stakable stake within a month or two.
As easy as dont allowing more than 1 wallet staking from same computer / IP (example). Not that hard (still could be "hacked" but at least we tried). How it is now, you dont even need to bother doing anything, just spread your UTOX and you will "own" the network. Nothing left for not big whales. My wallet is doing "nothing" useful from staking point of view. I would rather close it....not good for the network, dont you agree?