Here's something to consider: If you play Squeegee, then Counterfeit a Gold, then play a Gold regularly, do you get the "while Gold is in play" effect? Haddock and SCSN would say no. I think most people, without having put any thought into it, would say yes.
Squeegee also has an issue of, it starts happening when Gold is not in play, which is weird. As far as I'm understanding Haddock's interpretation of Squeegee, the effect waits until Gold is in play and then triggers, then ends when Gold leaves play. So what happens if I don't play Gold this turn? Will it trigger next turn when I play Gold? Or if my opponent puts Gold in play before I do, it triggers on his turn? None of these is more intuitive to me than saying that the "while" effect lasts for the duration of the game.
Think of it this way. Suppose I say "While I'm in the hospital, take care of my (blue) dog," but then it turns out I don't need to go to the hospital after all. Years later, I do end up going to the hospital. In either interpretation, you must now take care of my dog; the effect begins the next time I go to the hospital, which happened to be much later than expected. So that's not an advantage of the Haddock interpretation over the Awaclus interpretation. Given that it works that way, I would think it's more intuitive to say that the effect is permanent (by saying "while", I imply that it is true for every time I'm in the hospital for the rest of my life), than it is to say that it only applies the next time it happens (regardless of whether it happens when expected).