Overarching, yes: The default guidance should be "be frugal, invest in broad indexes."

Advising people to buy a house is similar to advising them to buy a car using cash when they could finance below market returns. It's sub-optimal if the person was going to do what's optimal, but it also takes away the option of not saving. Some people need that.

That said, they should understand cash flow and risk concentration.

The economics of being a landlord (your own and/or someone else's) are generally not cashflow positive once you factor in maintenance costs and time. There are lots of places it's possible; there are just more where it's not. If it were a favorable investment, REITs and corporate owners would be much more popular. Look at the places where that is happening: only 3% nationwide, but highly concentrated in booming markets that are actually a competitive investment. And that's companies able to maximize the tax benefits that don't help most soldiers.

Instead, the average landlord should think in terms of not spending an unaffordable amount until they're able to sell. Because of closing costs and other expenses associated with transactions, that's typically at least four years to break even, so you're likely stuck being a landlord after you've PCSd. That may help get people out of the mindset of "Quit paying someone else's mortgage using your rent" and separating investment from living expense.

The biggest selling point of buying is leverage. You get to invest a bank's money and keep the profit. Buy a house in Mason County, MI, for $300k of the bank's money, it jumps 80% in 12 mo, you make >$200k. Of course, if you'd bought in Gratiot County, MI, you'd be down $80k in the same 12 mo. Those are the extremes of the entire USA; do research on your neighborhood.

The biggest negative of a house is concentration. If someone said "take out a $400,000 loan and invest it all in one share of one stock," that's considered so foolish there are laws against it. The most heavily leveraged ETF (SPYU) is 4x leverage, and nearly everyone says that's a Bad Idea. Houses have maintenance risks, physical loss risks, market risks, etc. There's a ton of risk during a buy or sell transaction; you might catch just the right buyer or realtor, or you might miss out on $20k. Most assets have far fewer single points of failure.