I think part of the problem for Yanmar is that they have a premium tractor at a premium price. While they have a long history of quality, the market (average consumer) doesn't know them. Typically, foreign manufacturers come into the US with a low price point until they establish a network and sufficient name recognition. Yanmar seems to want to go head to head with JD and Kubota on price without their dealer networks and name recognition.
There is a dealer in East Texas now, but for me the price was too high with the risk they would bail and make things tougher. If I had that kind of money to spend, I think Yanmar makes a great tractor. Maybe their deal with TYM will help spread their brand better.