I was going to answer this, but it sounds like you figured it out on your own. If you want an umbrella policy, you will have to have high limits on your auto/boat...etc. It is designed as secondary insurance to pick up where your auto/boat/home left off. It is not meant as a replacement.
Generally you want to balance your assets against your liabilities to see if you need an umbrella policy. It is recommended for those with a high net worth.
I will take a stab in the dark that 99% of TR would
not need a 1 million dollar policy. There is another thread right below this where a kid wants to have the bare minimum state mandated $10,000 coverage and is bitching about that. Nothing wrong with that if you have low net worth or little assets. Anyone with a decent job, maybe a home and a family needs to protect themselves. Make sure you have uninsured motorist. It will protect you incase you are hit by uninsured or underinsured.
Consider upping your limits if you fall into that catagory. Its actually very reasonable to bump up your coverage to 100/300k
Insurance is a neccessary evil. I know all about it. I have muliple cars, a boat, a business, and a home.