For those who want to use actual tested times for waterbath canning tomato products, here is the NCHFP link. Tomatoes are generally around 4.3 on the pH scale so it doesn't take much for them to be close to the danger level. That's especially true near the end of the season when the plants are removing acid from the fruits. These processing times are tested with the addition of bottled lemon juice or citric acid, so if you skip that step, the times are no longer true.
For the rest of you, you can certainly do whatever you like.
Here in the West, there is a much higher incidence of botulism spores in our environment, so what works for you might not work out here. These times are tested and tested to be sure that the acid level throughout the processing and for months afterwards in the jar will be in the safe zone. They have ways of testing these things that weren't available years ago. I know that botulism is rare but it does happen and I don't want it happening to me or anyone I give/sell my canned tomatoes to.
http://nchfp.uga.edu/how/can3_tomato.html