Some like to operate that way because they doubt that the thing that they're "shopping" for will never meet the criteria.Isn’t that how life is? We decide some feature makes a purchase worthwhile?
I see lots of people who shop for TVs that way (I'm probably one of them). I want a TV that can do 3D but it may be too late for that. I want a FALD LCD with hundreds of zones. I don't expect to find one, but that's the straw man I've set up for myself.
When it comes to health monitoring equipment, I want the most accurate equipment I can get even if it isn't the most convenient or the cheapest.