With all due respect to your view which is shared by a number of members of Congress, I do not agree.
For one thing, if you characterize it as a death excise tax and make it payable at the time the estate is settled as is current practice, you run into the same enforcement problems and expense as you do with the estate tax. But for less money. So it is again a tax that costs revenue instead of brings in revenue. So why would you do that?
If you try for the same result by carrying forward the deceased's basis to the heirs so that you think you will ultimately collect capital gain tax at some point in future history when the asset is sold, you run into another set of problems.
The constitutional authority for the income tax is limited to taxing "income". As you look at current asset values, in large part, with obviously many current exceptions (less after the real estate bubble collapses), valuations in excess of basis reflect not increases in real value but instead declines in the purchasing power of the dollar. So much of this so called capital gain is not gain (or income) at all.
Now I know this argument comes up from tax protestors on a regular basis and gets shot down by the courts however at some point, someone is going to fund a real challange to the capital gains tax; on behalf of a real taxpayer who has an asset that is clearly worth less than it was worth in 1916 but which has a greatly inflated price as a result of inflation.
And get good quality expert witnesses from prominent economics departments; and put on a real persuasive case that demonstrates clearly that the tax is being levied on return of capital and not on income.
And do a thoughtful job of selecting the forum in which the case was going to be tried--either the Court of Claims or a district court with a judge who is open minded on the real legal issue presented.
The courts ought to kick the capital gains tax out on the grounds that it is not constitutional.
It wouldn't be hard to find such a case - there are a number of qualifying cases in real estate, many dating from the '40s or '50s. The problem is finding the funding for the legal challenge.
I suppose it's fodder for a class action suit, as repellent as I find those to be.