First things first: sorry you missed the birdie putts but I have to point out that the guys and girls with great putting stats are using exactly the same holes - at the same time you were missing your birdie chances there were probably thousands of people sinking theirs.
The holes are mapped from hundreds of thousands of HD photos of regulation holes at actual courses - your avatar is placed on top of those photos to mimic as closely as possible your position on the green, so sometimes the hole may look a bit smaller, or a bit larger.
It is not, it remains the same ...unless you have some kind of magical virtual ruler allowing you to accurately survey the world of WGT or have access to the source code. Either way, everyone is putting at the same holes and there are lots of people who are very good at it ...at this point in time, I am certainly not one of them.
Also wanted to mention that dinging your putts in no way guarantees they will drop - the "perfect putt" is the one that goes in, it's as simple as that.
Everything else is a miss and you move on - or you do the virtual equivalent of snapping your putter over your knee and shout about it a forum. Totally up to you, sometimes it's good to get things off your chest but I'm pretty sure WGT won't be increasing the hole size just because you missed some putts you thought should have dropped.
All the best on the next 10 birdie opportunities. Hit 'em hard and I hope they drop for you.