In our area, it is dependent on number of participants and what time you start. Last year, 10,000 people each day. If you started in the third or later waves it was a seven hour walk with obstacles. The course was mostly single track, so you couldn't pass and 10,000 people were way to many. The average ticket was $75, so you can figure out it is just a business. I think there are many other not so popular trail runs out there you can actually run. Tough Mudder is all about ticket sales in our region.
I guarantee you she spent twice the amount of energy you did. I've been on my fair share of long wilderness hunts deep in the mountains and as far as toughness goes tough mudder has been the most challenging by far.