Because very few lenders will lend to a business at this stage (relatively little revenue and short operating history), and the few who do will require a personal guarantee and/or personal collateral.
That is, if the business fails, or does okay but doesn't become large enough to service the debt, the founder still needs to pay the loan back. For all intents and purposes, a business loan with a personal guarantee is a personal loan.
That's not true of these terms. If the business fails, the founder doesn't personally need to repay the investment. If the business grows but very slowly, the founder still decides how much to re-invest in the business.
(Also, at the interest rates you mention, such a loan would be no different than taking out $100k in personal credit card debt to fund your business. Yes, someone could do that, but it has some very significant downsides.)
That is, if the business fails, or does okay but doesn't become large enough to service the debt, the founder still needs to pay the loan back. For all intents and purposes, a business loan with a personal guarantee is a personal loan.
That's not true of these terms. If the business fails, the founder doesn't personally need to repay the investment. If the business grows but very slowly, the founder still decides how much to re-invest in the business.
(Also, at the interest rates you mention, such a loan would be no different than taking out $100k in personal credit card debt to fund your business. Yes, someone could do that, but it has some very significant downsides.)