Les,
I did a bit of fact checking on you assertion that older folks are the owners of most of the savings. According to 2 year old numbers from the conservative organization "The Los Angles Times", it breaks down about like this. I guess it depends on what you consider older.
Folks 55 years and older account for about 38% of savings.
Folks 45 years and older account for about 70% of savings.
I consider your assertion "reasonable".
I could not find any good defense of your concept that taxing LLCs would be a good way to make the tax on the interest more fair.
Somehow I have a feeling that LLCs might be owned by the same people who get older and save money....