App-lock / anti-theft seems pointless

I'm a bit confused regards app lock. It seems there's no way to stop somebody from simply uninstalling BitDefender from my tablet to remove all security features. The only way is to lock the whole tablet behind a  passcode. However, I don't want to use a  passcode every time I turn my tablet on - and prefer to use the BD app lock feature instead. Reason being that app lock allows me to use 'smart unlock' feature, so if I'm on my home wifi I don't need to use a passcode - which I find really annoying. But, as I said before, nothing can stop a thief from uninstalling BD from my device. So, if I am forced to lock the whole tablet behind a passcode, the app-lock feature seems a bit pointless, because if I need to use a passcode to access the device, why would I need to lock any apps - seeing as the whole tablet is locked?

 

Same goes for anti-theft. A thief would simply uninstall BD unless the whole tablet is passcode locked. So what's the point?

 

Isn't there any way to stop somebody uninstalling BD? Or at least to force them to input my anti-theft passcode when they try to uninstall it? Seems a bit silly to not protect the app from uninstallation.