It's understandable. However, you are not being asked about a future purchase. You are being asked whether you would make the same decision that you made to buy the car, knowing what you know today. When you answer that question you factor in all those issues which you have with the company as everyone would. If amongst all the possible answers you choose "definitely yes" (not maybe, or possibly) that would be a pretty strong indicator that people are happy with their decision.
It doesn't invalidate the fact that there are issues that Tesla needs to work on, but in comparing Tesla's performance to other car manufacturer's, that's a pretty outstanding result.