There's a reason why Warren Buffett calls his jet "The Indefensible". There's no way you could ever rationalize the cost, other than flying private planes is freaking awesome.
This is the reason why all of the BS exists around flying commercially. If truly wealthy individuals had to suffer through that, airport security would have been dismantled years ago.
Arguably even into the country, if the other agencies are doing their jobs, and assuming the threat is foreign.
Private planes are absolutely awesome for getting between inconvenient points domestically. Have to get from San Jose to Austin on short notice? A quick skim of ITA shows coach fares of $1k and they all require a stop somewhere, with an average duration of 7-ish hours.
Or, hop on a private jet, skip security, take off pretty much whenever you're ready to take off, nad then come back when you want it.
Just kidding :)