I can count only three official published problems I've ever seen (among many thousands) that I find mathematically questionable. There's one problem that appeared in an older version of GMATPrep which had the wrong answer (they forgot about negative numbers!), one DS problem which can be solved without any statements at all (an absolute value/inequality question that has been posted on BTG many times), and then there's this problem.

I entirely agree with Kevinst that it makes no sense to talk about the x-intercept of the line y=0. So I find it perfectly reasonable here to think Statement 1 is sufficient - it appears to rule out the possibility that the line is horizontal, so it seems sufficient to give a "no" answer to the question. But of course if you consider x=0 to be 'the' x-intercept of y=0, it isn't sufficient.

While this question is pretty terrible, you can at least take comfort in the fact that the number of bad official questions is negligibly small. So you are almost certain not to encounter this kind of ambiguity on your actual test. And if your answer to this question was different from theirs, don't worry about it.