Great point. If anything, I think the best thing these tests and others like them do is give us a framework to understand ourselves and others. And I think that the more detailed the test is, the greater understanding it affords those who take it.
Another test I'd recommend (which I unfortunately can't find; I'll keep looking!) is an extremely comprehensive Harry Potter Sorting Hat test. Rather than answering multiple choice questions, it has you rank your responses on a scale, then tallies your results and tells you which House you'd be in based on your percentage of compatibility. I got 98 percent Ravenclaw and 79 percent Slytherin, which I compared to my brother's 95(?) percent Gryffindor. It's a slightly nerdier way to understand personalities.
Edit: This one is close to the one I took, although it has a long series of true/false statements rather than asking for a ranking of one to ten. Not sure if it's different, or if I'm just remembering it wrong.