It may be that data transferred from your 2015 return (if you used TurboTax last year and transferred that data over to your 2016 return) that contained self-employed information, or you may have entered Form 1099-MISC which requires TurboTax Self-Employed.
If you feel that you do not need the higher version of TurboTax, you can clear your return and start over to downgrade (as long as you haven't paid for or registered your account), instructions here:
https://ttlc.intuit.com/replies/4248526
