In all seriousness, I don’t know why you thought about this, though your concerns are justified.
Also, I do NOT think it will dilute your efforts.
Think of your website as your office. Obviously, there are a ton of ways to get there, and Facebook happens to be one of the transportation methods.
Basically, social media IS one of the gateways to your website. Aside from which, can you actually interact with your website’s visitors through your website? This is what social media is for: it’s provides a way to interact with your audience, which is why it is of utmost importance.
And no, it doesn’t make people think that your company page is THE company website, as long as you make it clear in the FB page’s description and posts. 