Hi Hans, very good article!
Design thinking was born in the architecture and urban planning circles that are both very multidisciplinary in nature.
Take a look at how LEED certifications are done in the world of green building. It starts with a conversation between multiple stakeholders and parties with different expertise.
I don't think specialization is a bad thing because the path towards multidisciplinary goes through good facilitation of a conversation between different specialists, as well as organizational maturity. If you have these two things in place, you can pretty much start tapping into multidisciplinary teams that involve many specialists working towards the same goal, each contributing specific knowledge. I think many organizations just lack the methods and frameworks of facilitating interdisciplinary work.
Those organizations that have the frameworks eventually make some of the specialists not only work with other disciplines but also learn more depth what their counterparts do.