You can't have it both ways. If you are arguing that BAH should pay for the bare minimum and have perks for rank/seniority, then everyone should have to live in the barracks until O-4. No space or married? You get 50% of the median price for a studio in your geographic area for E-1 to E-6. E7 and above and JOs get the median for a 50% of a 2 BR, O-4 and above get the median for a 1 BR. Anything living arrangements beyond that is a choice the servicemember makes and not provided as an allowance.
If you decide to start basing it on need because that would be unpopular, you now buy yourself into the same situation we are in now - providing an allowance based on varying need and not just based on rank/TIS. You are just quibbling over where to set the bar, which requires making assumptions about the 'typical' family size/situation for a servicemember of a given rank. Those who don't fit the assumption can stand to make (or lose) a lot of money. Even collecting leases will do nothing because a smart servicemember will rent the max allowed benefit or even over the max allowed benefit and then sublet a room without telling the Navy about it.
The current BAH system isn't as terrible as people make it out to be. What we're really talking about is how newly minted JOs writ large have been able to milk BAH because they are usually single and can find a place well below the asking price. I think if you polled married enlisted sailors w/ children, you'd find that they don't think BAH is nearly as generous. They don't have memories of several years of pocketing 25-50% of it tax-free and have difficulty finding a place that meets their needs within BAH if they can't get a house on base.
It's possible because the gains for TSP are paid from the pooled growth of the stock market and not from the DoD's account.
Even with the proposed 5% match, 5% of Ensign or LT pay into a TSP is cheaper than 10% of O-5 pay plus COLA raises until the member and his wife pass away... ditto for the enlisted payscale.
I didn't argue that it should pay the bare minimum. I argued that it shouldn't pay for differing personal choices, like family size. I see this as totally different. Giving everyone a studio, per your suggestion, or giving everyone (or everyone of the same rank) a 3 bedroom SFH, treats them all the same. Giving the ones who marry an extra $100 per month clearly does not.
So no, I'm not quibbling over where to set the bar. Every O-4 in San Diego gets $2900. Every O-1 in Jacksonville gets $2000. (Numbers totally made up.) EOD.
I don't think the BAH system is terrible. I do think there's shouldn't be a different pay based on family size, but that's a relatively minor thing. There's a few other tweeks I think make sense, but I don't think it's terrible, and I didn't recommend total overhaul. In fact, I argued against making it a use-or-lose, like OHA.
And I don't think you can/should count gains in TSP as part of the compensation. That's not money from the government, that's money from the stock market. Money that would be just as available outside the compensation package. Also, do you really think all or even most people are going to actually contribute enough to get that 5% match? Not going to happen. And of course, there's the risk of *losing* money, too.
If I'm figuring out how much someone is paid, I don't look at what they do with that money and how it grows. I look only at what money they are given. If I buy a home with my salary and it bring in $5000 in profit per year and appreciates by $30,000, I don't calculate my salary has having been $30,000 more per year based on the growth it allows me to buy. And in the same way, I don't count the growth in my 403b as part of what I was paid. I count my employer contribution, but not the growth. That's the standard way to calculate compensation. Using the growth of the employer contribution (and maybe even the employee contribution required to get the full match, if theses studies are being really underhanded) is nonsensical.
It's entirely wonky math. Mostly, it's propaganda made to look the new program more desirable.
So if we go back to calculating in a less disingenuous way, we are back to this new system paying people less overall. Which is fine. The labor market will adjust accordingly. I don't think it's necessarily bad, but I do think that manipulating the numbers to claim otherwise is shady.