"If you truly are a diversified investor, you try to manage appropriate holdings and activities in the account(s) that have beneficial treatment for that type of activity."

Maybe, but maybe most of their assets are in tax sheltered account so that account needs to be diversified.  Or maybe they want to retire early and have a shorter time horizon for the assets outside of the IRA.  There are lots of maybes which is why it is silly to make a blanket statement of how you should invest in an IRA.

"It's interesting to see the reaction from someone who is so proud of appreciated stock value (well, until a few weeks ago...) in their IRA, and their own investment accounts are not as aggressive, because they thought only the Gain on Sale would be taxed from the IRA"

I'm not even sure what you are saying here.  I doubt know that most people think only the gains on their IRA would be taxed.  And if some of my accounts were to decrease in value dramatically, I would probably prefer it to be the account that I don't plan on drawing from anytime soon.

"And there is no real Math to do for this event; it's just a Value for the property given. Basis, gain, etc, is moot."

Exactly, which is what your initial answer should have been, but instead you chose to not answer the question and leave several comments just confusing the original poster.