Actually, it is not really a problem: having some of your answers counted as errors does not hinder the learning process. Consider the trial-and-error phase as a full aspect of learning, and remember that you are not really punished in any way, apart from earning a little fewer points, which is only an artificial trick to make you learn the language. :)
The "bonus points" undermine the whole thing as it distracts from the whole goal of learning and makes people focus on being right and "streaks" rather than playing with the language, testing alternate ways of saying the same thing, if even making mistakes on purpose. Of many changes on here that I disagree with, that was one of the worst and I'll die on that hill. But yes, agreed the trial and error aspect is itself a useful and instructive part of the process.
Even in Vancouver, British Columbia, Canada, some Japanese restaurants will greet all customers this way, with the host or hostess saying it as the customer enters, followed by the other front-of-house staff (bartender, wait staff, etc.) repeating the phrase in unison, and with enthusiasm. It's especially common at the few izakaya we have here.