The "Estate Tax" may not affect the bottom 95% of the populace (at least not directly) but it really doesn't hit the top 1% either. It--like a great many of the liberals' favorite taxes--targets those who are "making it", but aren't there yet.
If someone has a few million dollars in assets but needs to keep most of their assets liquid in their lifetime (e.g. a family farm or business) they'll get clobbered by the estate tax. Those who don't need to keep their assets liquid can generally avoid the estate tax. To be sure, a billionaire is likely to keep a few million dollars of assets liquid and so may pay more in total estate taxes than someone with a business worth just over a billion, but the much larger portion of the billionaire's wealth will escape taxation.
Given that illiquid funds generally produce less tax revenue than funds which are kept liquid, the government--by encouraging wealthy people to set up various trusts, foundations, and such that are immune from estate taxes, also encourages them to stash their money in a way which produces both less revenue for them and less revenue for the government than other means which they'd otherwise use.