You're wrong. "Not too great" doesn't mean I had completely no idea about the language, I was able to spot
most obvious mistakes or strange constructions in the translation . Plus, 1,5 year later my Spanish is much better and I still think GT does amazingly good job for a machine translation. I also can compare it with how it works when translating from/to Spanish or English to/from Polish and really, English <-> Spanish is much, much better.
I'm fluent in English and Spanish. Yes, GT's English -> Spanish output is better than gibberish and you can often get the gist despite the glaring errors, especially if you know both languages.
But my point was, don't you think there's a bit of cognitive dissonance to somebody using machine translation because they don't speak a language very well, yet confidently asserting that the translations are good?
It might be like that but the point of my original post was that the correctness of the GT job was verified by native Spanish speakers (one might say it's a sort of a Turing test), not that my Spanish was bad so I thought translations are done good.