It’s funny you mention apartments, because that is exactly the comparison i thought of, but with the opposite conclusion. If you buy an apartment with debt, but get positive cash flow from rent, you wouldn’t call that unprofitable or a bad investment. It takes X years to recoup the initial debt, and as long as X is achievable that’s a good deal.

Hoping for something net profitable including fixed costs from day 1 is a nice fantasy, but that’s not how any business works or even how consumers think about debt. Restaurants get SBA financing. Homeowners are “net losing money” for 30 years if you include their debt, but they rightly understand that you need to pay a large fixed cost to get positive cash flow.

R&D is conceptually very similar. Customer acquisition also behaves that way