Let’s say you have $100 in revenue, $100 in salary expenses and $50 in other expenses.
Pre 174 you would be considered to have a loss and wouldn’t pay taxes on profits since you don’t have any.
However, post 174, since you’re amortizing salary expenses, you can only deduct $20 out of that $100 (actually the scaling is a little weird I believe, so it’s even worse and the first year you can only set aside 10%), so as far as the IRS is concerned you made $100 in revenues and $50 + $20 in expenses, so you had a profit of $30. So somehow you now need to find actual cash to pay for the $30 in profits when in reality you’ve paid out more than you’ve made.
This just means you have to raise more funds for something that is not returning any value to you.
Your competitors abroad don’t need to do this. Your deep pocketed large competitors don’t need to do this. They have cash to pay and they will get the money back in 5 years, a time which you may not even survive to receive that set off.
This is the worst kind of policy because it doesn’t even make the government more money (the overall tax deduction is still largely the same) but it makes things way worse for companies.
To take a simple example under Section 174 rules let's take a bootstrapped business with one US-based developer developing a SaaS product. If you pay them $100K and also bring in $100K revenue, prior to Section 174 the taxable revenue was 0. Under section 174 the business now can only claim $20K and the taxable revenue is $80K. Your tax bill is some fraction of that after you get done applying credits of various sorts.
The problem with the Section 174 change is 2-fold. It was unexpected--most people assumed it would be corrected. It also hits bootstrapped businesses hardest, which are exactly the sort of businesses we should be encouraging. VC-backed businesses have less of a problem early on because their expenses tend to be so high that even with Section 174 they aren't profitable. However even there as a founder there can be a substantial impact, because the Section 174 charges eat up your Net Operating Losses (NOLs) which you can use to offset the profit from selling the company or future tax bills.
Edit: as others have pointed out the amortization schedule is apparently not linear, so 20% might not be right. The other complication is that there are many deductions and adjustments that affect your taxable revenue. NOLs are the biggest in my experience but there are others.
When I bought a laptop for my business, it was amortized over... 3 years I think. Kinda nuts but, whatever. It's a couple thousand dollars.
But the example above (somewhere) with the 5 employees at $200k/each... only being able to deduct $100k of that, even assuming $1m in revenue... meaning 'profit' of $900k.... it's just crazy.