Unless you are speculating about tax policy, there is basically no case where you would want to do this. Losses now are worth more than losses later in terms of corporate tax. And if you are a startup burning runway, you might not live long enough to actualize the loss if you amortize it. From the perspective of day-to-day operations: the software engineers need to get paid, and that money has to come from somewhere, revenue, a loan, or the bank account. It's very much not spread out over 5 years in terms of your actual cash flow needs.

Typically businesses amortize large capital expenditures, and this allows the business to appear profitable even when they had a significant outbound cash flow. This is just something they're allowed to do with accounting in the US. There's an argument that you should take out a loan for situations like this, because then the cash flow events will more closely match the changing value of the business.

I would not try to make sense of it in terms of business accounting, there's no deeper understanding of business to be had. It's just politics; and it made it objectively harder for startups with revenue to survive and grow.