From memory one of the early controversies of STEEM was the ninja-mine for which I believe Dan wanted that stake distributed to new users and was of the understanding that it would be. I could be wrong, but this approach with Voice would be consistent with that sentiment.
The idea being to create a level playing field at the start of the project with no insta-whales or hugely unfair advantage granted to early adopters.
Although, it was also stated somewhere that the amount of Voice tokens to be distributed will decrease with time - so those that arrive first on the platform (and possibly are most active) may still have the advantage over later arrivals...