I've never give this one a try, neither seen it on any table (as far as I remember). So the reasons I expose here are just an educated guess for why it doesn't see play, but it doesn't seem hard to find.

Low strength, low trace, dubious effect.

Why would the Corp spend money to dig through the stack only to choose one card to trash ? Ok, they can order the drawn cards as they want, but still.

Why would the Runner prefer to pay any instead of trashing one not-yet-drawn card ? Not confident enough in their deck ? And then, a not-very-frightening sentry stand on the table, that can be passed through with few threats.

And also, why, why, oh god WHY, does this dog appear on Emergency Shutdown ? Has Data Hound ever been the chosen ice for this ability ? If you have witnessed such a madness, or even made it, just tell us. We want to know.

After he essentially won me a game, I feel like I have to make a stance here for the poor little doggy.

For 1 rez cost it can tax the runner 1 or 2 to pass it unharmed. Pup is another dog that is praised for doing the same thing. And for what it does, 2 strength makes it pretty resistant against Parasites compared to other "tax the runner a little and let him through" ICE like Pop-up Window. So if it is broken or the trace is matched, it's a nice little porous taxing ICE. There will always be need for that.

But what if the runner just ignores it? Well, that's exactly what you want him to do. Put this thing on a server they check regularly and you basically get a Stack lock similar to an R&D lock, but on the other side of the table. You filter what they will draw and trash the cards you don't want them to see. So it grants you both milling and information.
The milling can be good in decks that want to exhaust the runner's resources and the information can come in quite handy in a lot of decks, but is especially good when combined with Targeted Marketing in-faction, because you know what they will draw before they do and have time to set up accordingly.

All in all it's an okay ICE, that can be a small tax or a small advantage for a very small price. Until Improved Tracers hits the table.
The agenda itself is awesome, but it's even better when combined with a whole lot of cheap small nuisance Tracer ICE like Data Hound, Turnpike or Matrix Analyzer. It won't stop anyone, but they better pay the tax or face the consequences.