From a VC perspective, probably all the better: you've just shortcut a huge phase of R&D and can get right into marketing and sales. As long as there's some viable route to clean up any licensing issues (there almost always is).
You're thinking ethically; without the shrewdness and single-minded focus on profit that VC's have.
If you are so inept that copying someone else's codebase wholesale is what makes you a viable company, then perhaps you aren't worthy of investing in.