The BS Dealers say about 8K KM (5K Mile) intervals is crap...Again that car was all commuting with very little city driving.
To be fair...your use of your vehicle is pretty atypical. Per your account, you do very little city driving and almost all of your miles are steady state highway driving. An interval of closer to 5k miles probably is appropriate for what I'd call a "typical" Pilot driver, who experiences a lot of short trips; waiting in the drop-off line at school or daycare; stops at the grocery store, park, soccer, etc. I'd still advocate in general that folks heed the advice of the maintenance minder, as it may recommend a change
prior to reaching 5k miles in some cases. If your statement is about fixed intervals in general, then I agree -- everyone's situation will be different and a fixed number, whatever that number might be, won't be appropriate for everyone.
Of course, one of the reasons for the long oil change intervals on heavy duty trucks, besides their use case of lots of highway miles at relatively low and steady engine speeds, is the sheer volume of oil in their sumps. A Volvo D13 holds somewhere around 40 quarts of oil -- about 10x the average capacity of a passenger car engine. With such a high oil volume, it'll take much longer for that oil to degrade to the point of needing changing. And Volvo's recommended change intervals are between 30k miles and 60k miles, depending on fuel economy (which I think is an interesting way to specify an oil change interval), which is also about 10x the average recommended change interval for many passenger car engines.