I "voted" for PP with my wallet back in the Kickstarter days. And I would vote for PP with my wallet again if they ever produce something to purchase. But I have no interest in having to purchase another game just for the right to cast a Yes vote for PP.
Technically you didn't vote with your wallet with Kickstarter as no monies were taken from anyone that pledged, but I understand what you mean.
Also you have to remember, it is not PP asking you to purchase a game to vote, that is Steam (Valve). It just happens that PP opted to try and Greenlight Perfect Golf on Steam as it is a thriving gaming community with millions of users, but like Ian D has stated, it isn't for everyone. I personally cannot blame PP for trying the Steam option. Many Indie games are going that way too and reaping the rewards.
I have followed the Greenlight push (as I use Steam) and it has gained plenty of positives from Steam users, who all seem to agree that there is nothing like Perfect Golf on Steam and they are adding their YES vote to get it on there.
How PP manage all this and how they make the game, TI and CF available is down to them. iRacing have also gone for Steam Greenlight but they did also add that the current non-Steam way af accessing their service would not be lost, so there must be a way for both to co-exist. If so, let's hope PP give plenty of consideration to this option.