They are expenses, but amortized over 5 years. So if you spent $2m on employee salaries, you would then deduct $400k from your revenue every year for 5 years.

If your employee expenses remained constant, then by year 5 you would be deducting $2m from your revenue since you'd be accumulating the deductions from the previous four years.

So in steady state it wouldn't necessarily be a big problem. But for a startup which is hiring many new employees and whose revenue is growing it's a huge problem.