For example, one team has spent several weeks and thousands of dollars to get another team's SOAP integration working correctly, when it would have taken five minutes in REST.
The codebase did not follow a "elegant" practice and is an absolute spaghetti mess. Things that should take 30 minutes take one week and this add tremendously to personnel cost.
I agree though that working together is tremendously undervalued. A decently smart person can be taught anything (which is part of the replacability problem you mentioned), but how to not be an entitled ass is nearly impossible to teach in a workplace environment.