"Easy" is subjective, unfortunately.
Whilst that's not an expert question, I personally don't know enough about vegetable gardening to say "X is the easiest vegetable - you can't go wrong with X!" I could guess and pick one, but I wouldn't have the in-depth knowledge to explain why. I'd prefer this question to be "What is the easiest vegetable to grow?" so that it encourages a more precise answer with reasoning behind it ("show your working").
Yes, we should be trying to remove questions that 90% of the world can answer, because we won't attract expert knowledge otherwise. I think we do this by changing "easy" questions into ones that give a similar answer, but require more knowledge to answer well and we reward well-explained answers appropriately.