You could own 5 restaurants of that size and not pay estate tax.
[1] http://sellingrestaurants.com/news/how-much-is-a-restaurant-...
On your last point- a traditional corporation won't fail if one person dies as the issue of ownership is inherently divested from any individual person. Stocks are one of the easiest assets to liquidate on this planet- I'm not seeing an issue there. The restaurant? It would be sold. If I have a family member who I actually think could run it adequately they would be able to purchase it like anybody else and I would encourage them to do so while I was still alive.
More Polyanna thinking that anything you can make up in a minute, won't be gamed to death by anybody and everybody. Why? Because almost everybody wants to increase the chances of their children/heirs succeeding. Its built into the species.
Obviously such a system would need significant safeguards- this is something we're both fully aware of as intelligent human beings. Mentioning them now is just a strawman unless stated as the overall opinion "it's 100% impossible to stop abuse".
On your last point, I find it silly to assert that a belief in humanities ability to overrule animal instincts is somehow "Pollyanna thinking". Everything we've achieved thus far as a species has been based on that belief.
But everything in the tax law is a testament to how this is playing out in reality. Try as you might, 10,000 lawyers will push their pointy noses through loopholes to benefit their clients, which is everybody.
[1] http://www.irs.gov/Businesses/Small-Businesses-&-Self-Employ...
Just because something is idealistic doesn't mean it's incorrect.
> You trust the govt to spend your wealth, more than say a relative?
Dear God yes.
And 'wealth' isn't all gold buried in the back yard. Its also investments in businesses (either stocks or directly) as a corporation or even a proprietorship. Who runs the restaurant after you die? The government? Preposterous.