[AtlUmpSteve]

Because generally attempted deception is an inherent part of the game. Let's take your argument to the outrageously end of the world degree.

R1 on 3rd, B2 hits grounder to F5. F5 fakes a throw to first, drawing R1 toward home, then tags out R1. Clearly, the fake throw deceived R1.

Now, answer your own question, Shane. Does(n't) deceiving the runner fall under the definition of hinder or impede? Are you ready to call this play obstruction?

I would like to assume you would consider this an outrageous misapplication of the rule. If you do, then the only next question is where do you draw the line between acceptable deception and unacceptable deception?

The rule book makes clear that a fake tag is a specific unacceptable deception; and most would agree that the likely unsafe and unhealthy reaction of runners is the rationale. I submit you use that thought process as your guide; if the deception of the defense puts the runner at a physical risk, you should (at least potentially) consider it obstruction. If the deception runs closer to gamesmanship, it is an acceptable part of the game.