Couple of arguments against such exemption that I can see are
* major real estate property owners can make a case (in court of necessary) that their property prices have not increased as much as single-family residential prices, due to the nature of the commercial market (fewer buyers, larger amounts, larger variety of the market to find decent comparables)
* as property tax is deductible, the revenue would just restructure - what will be collected via property tax would then be deducted at the end of the year from income tax. I guess even in that case owners would be supportive, as property taxes typically go directly to the municipalities, while income taxes are spent by some politicians in Sacramento, but then why would Sacramento be in favor of the exemption that would lower its collected revenue?
This is like leaving the front door off the law, not like putting a back door into it, so I wonder if it is more of an internet rumor than an actual way to avoid change of ownership. Maybe people do it but it is fraud?
It seems it's more complex than what I implied, though. The property needs to not only be owned by a holding company, but sales of the holding company have to be structured in such a way that overall ownership of the holding company isn't deemed to have changed. If the above article is correct, that's triggered when a new owner acquires a majority stake. So to avoid triggering a change in ownership in this case, Dell structured the sale so that he, his wife, and another business partner all bought interests in the company, split so that no single purchaser acquired more than 49%.