If you go to Youtube and look for "design thinking" you will find a large number of videos with TED talks and other talks all explaining what design thinking is, how important it is, how to do it, etc. Some are good. They present an understanding of designing that is ok, but in many cases they are quite simplistic, and surprisingly quite often based on the speakers personal experience of realizing the "power" of design as a new creative process to solve problems. The speaker have "seen the light", and the light is design thinking. Again, this is all well, we do need as many as possible to be introduced to a designerly way of thinking. The world needs design thinking.
But, it is not enough. Any approach used by humans to engage with the world in an intentional way, for producing knowledge (as the scientific process) or for producing art (as the artistic process) or for producing change (as the design process) has to be supported. The scientific process has for the last couple of centuries been develop within a larger culture that recognizes, enables, supports and advances it--the academic culture as manifested by universities. This academic culture has developed together, in parallel, with the scientific process. The two have over time influenced each other, and they have more or less had a common goal. The broader academic culture knows what a scientific process is and what it requires to be successful and it sees as its task to make that happen.
If we now look at design thinking instead of the scientific process, a very different picture emerges. Design thinking is in most cases not protected and supported by a broader culture such as the academic culture protects and support the scientific process. When I talk to professional designers in all kinds of industries this is one of the most frequent 'complaints' I hear. these professional designers are happy to be involved in design, but they do not feel understood and definitely not 'safe' or protected. Instead, I often hear them describe their reality having to 'defend', 'explain', and 'fight' for design as a suitable approach. They feel threatened and are always looking for ways to argue for what they do, even to the extent that they start to change the process to look more like processes that might already be recognized and appreciated within the culture where they work.
This is why design thinking (in all its varieties) is not enough. Any design approach needs to be situated within a designerly culture that understands what design is, what is requires, and when it is appropriate (and not). Design thinking needs a surrounding culture that protects its strengths, uniqueness and core so it can perform and deliver what it promises. Companies that bring in design thinking as a quick fix, as a 'tool', as a 'method' will fail unless they engage in creating a broader designerly culture.