It is not only acceptable but required that you love your product.
Why else would you spend 1000s of hours building something if you don’t love it?!

But please understand what exactly is it that you are loving. 
Don’t blindly love your product because it is what you build.
Don’t be attached to the creation, rather be attached to the impact it can make in the lives of your users.

Love the problem that your product is solving. 
Love the delight your product brings customers.
Love the UX journey that makes the solution practical.

Most importantly, love being able to make changes based on feedback. It might mean killing a feature you spent hours building (and identify with) or it might mean making a pivot away from the original idea.

Founder inflexibility might be more dangerous than a well-funded competitor!