Yes. Because the IRS matches Forms 1099-MISC and would send you a notice later in the year indicating that they found unreported income on your account. This would require a time-consuming explanation from you, time better spent earning more money in your business.
TurboTax gives you the ability to report income for which you have a 1099-MISC and income for which you do not have a 1099-MISC (cash or over-the-counter sales). If all of your income was transferred from QuickBooks onto one line of your business tax return, simply enter your 1099-MISC forms, then manually subtract the total out of your income amount reported by QuickBooks, so that the gross income on the tax return sums to the income from QuickBooks.
