While I do realize that Crane is not useless in theory for the obvious reasons (Oltarus mentions them), I do believe that it is totally useless in practice because:
The game ends at 12 buildings, and you can only build one at most each turn. Furthermore, each time you build your opponent(s) will also have the chance to do the same. This means that if you are not gaining the same amount of VPs (on average) as your opponents each time anyone plays the Builder, you are falling behind. Given that almost all the big VP producers (including the overpowered Guild Hall) totally depend or at least work better when you have a large number of buildings, it follows that Crane is not the best for your VP total.
Also, since Builder will be selected almost in every turn, players not using Crane will be constantly moving towards ending the game (and improving their board while they do so). Using Crane requires you to sacrifice one building opportunity (for the Crane itself) and play with less buildings than your opponents (an additional 1 building less each time you opt to use the Crane), which means that you get less building abilities to work with. But you do want to use the Crane (why build it otherwise), resulting in what is a death spiral to my eyes.
I have never even considered using Crane when playing against seasoned gamers -- it was obvious to me that they would end the game with many more VPs than me while I would still be at 9-10 buildings at most. I have used Crane successfully against much weaker opponents, but that doesn't mean the card is good (I would have won using anything, really).