There are worse coins out there.
How many do you think know about that the top 5(!) Addresses owns more than 50% of the entire wealth on their system.

This is usually how it is with cryptocurrency, it's nothing specific to Gridcoin. The distribution can be debated to be good or bad, but the fact is that there was people there before anyone and they got a bigger share.

The fact that 50 addresses owns 50% isn't weird and they most likely belong to a few of the very early adopters, plus Rob plus the foundation funds.

As I write in my post about Golem vs Gridcoin.

https://steemit.com/gridcoin/@sc-steemit/why-golem-falls-flat-compared-to-gridcoin-network

Main Concern is that 5 users owns 50%+ of Golem
My biggest concern about Golem might be the fact that just 5 addresses owns 51%, and 3 of them hold a staggering 44%! The fact that this coin is so centralized might be something not that many think about.

Source: https://etherscan.io/token/tokenholderchart/Golem?range=5
Comparison on Gridcoin
Top 3 Users owns 30% of all coins
Top 5 Users owns 35% of all coins