I always take off the lower leaves and plant as much of the stem as possible. I leave only the top set of leaves. The plants do grow adventicious roots and if I leave more stem, I just get a taller plant. Except for tumbling Tom which is a basket tomato, the tomatoes I grow are caged and usually 7-8 ft by the time they are in full production. I grow them in 18 gallon containers and the roots will still go out of the pots and into the ground. Tomatoes need a lot of root space as well as headroom.
What I find is that most beginners choose a pot that is too small and don't plan on a support system at the start. The support system should be in place when the tomato is planted so it is strong enough and does not damage the root system when it is being installed.
The other thing that beginners often don't realize that plants are living things that need air, light, water, food in the right quantities and that all things have a life span. They don't live forever.