... and OpenTable is well-known for being a really bad business partner. PF Changs is a simple example- this is not just happening at the high end. At very least, you don't have your own customer data housed in your own system and OT has the right to market to your customers however they want.
Could you provide some links that bear this out? Not the onesey twosey whiny restaurants that could pony up but choose not to and then manufacture reasons why the don't want to. A couple of articles that speak about massive restaurant dissatisfaction would do.
We hear this canard all the time. "Opentable is bleeding us dry." Except that thousands of restaurants have joined OT and managed to stay in business for years. Every 12 months or so another Great White Hope OT alternative surfaces. "We're going to take OT's customers away and our service will be free to restaurants!" Except it never happens, at least not in a significant way.
I understand that restaurants are a low margin business but I'm in no way nostalgic for the good old days of phoning in for a reservation and having the phone ring 15 times, then being told "please hold," then waiting 10 minutes, and then having the line go dead. OT is infinitely more reliable than that and has the added benefit of being available 24x7.
That "OT is stealing our relationship with the customer" line is also specious. I get regular promotional emails from restaurants every week. Almost all of them are the result of the fact that when I made an OT reservation I checked the box that said that I wanted to receive promotional emails from the restaurant.
OT (or a successor service) is here to stay. Restaurants may kick and scream but the world has changed.