That is correct. You invested $100k in developing a new product. Even if you fired your developer today, that product will earn you income for years to come. The general principle is that when you make investments (versus pay operating expenses), you can't deduct the cost of the investment up front, you have to deduct it over the "life" of the investment. In the case of developed software, it's "life" is deemed to be 5 or 15 years for tax purposes.

Previously they made an exception for some kinds of R&D (versus other kinds of investments), so that they could be deducted all in the first year, within certain parameters. The TCJA took away that special treatment (to pay for overall tax rate cuts).