There are many factors that can affect book value, both up and down. As you rightly point out, in many industries, a fixed asset (such as building) only have value to the company that built it. As a more extreme example, Boeing has buildings for assembling aircraft that would be of much lower value for any purpose other than aircraft assembly. That, however, does not mean that the buildings are worth only a fraction of their cost; though in a forced liquidation they would not sell for anywhere near their carrying value.
Conversely, if an asset has been fully depreciated, it will be carried on the books at no value (or only salvage value), even though it might have considerable value.
Book value also does not include franchise value, which can be a significant asset for a company with a good reputation (such as TKR).
For myself, part of my screening of investment prospects focuses on companies with strong financial positions; little debt, good current ratio (ideally liquid assets exceeding total liabilities), good interest payment coverage, and fixed assets that are reasonably well protected against diminution or impairment.