The idea that this is leading to mass developer layoffs is an overstatement.
The total amount spent will ultimately be expensed, whether immediately or over five years. The sole impact is on the time value of money, which I don't believe warrants the current scale of developer dismissals.
Also, the claim that taxes are levied even during a deficit seems incorrect. While I'm not familiar with US tax law, it's typically possible to carry forward losses.
For example, if a developer is hired for five years at $100 annually, the expensed amount in the fifth year would still be $100, even after any legal changes.
It means you need more money early, to pay taxes on theoretical future profits. That means it costs more. That means you can afford less on the same money. That means that you need to lay off people to maintain the same costs.