It's so heartening and gratifying to see how popular design thinking has become and how widely it's been adopted. With that popularity also comes those who simply learn a subset of methods in order to hang out their shingle as a "design thinker". Some will argue that doing some design thinking is better than doing nothing. I disagree. I think you need to do it right in order to glean the benefits of it. I think you can do more harm if you don't do it right. In fact, I think we should adopt the physicians' Hippocratic Oath to "do no harm". 

I've had a chance to observe design thinking being described, taught, and practiced at numerous institutions and organizations worldwide and have concluded that there are three major ways that I think some practitioners fail to do design thinking properly which, in turn, can have a negative impact.

1. No User Research. A common practice is to start doing design thinking by using an Empathy Map exercise. However, if the team hasn't done any user research in order to understand the user, the value of the exercise is questionable because participants will simply be "making it up". And if the results are summarized in a persona the negative impact is further amplified. The team may think that they've accomplished something by empathizing with their users but they've done something worse, they've created a made up summary of a user that doesn't have any basis in fact. Human beings are wired to recognize people and internalize key attributes of the people they meet. If the team created a made up person with made up attributes, they're going to recognize and internalize that incorrect information. To mitigate against this, the team should first carry out user research using methods like ethnographic observation and structured interviews and then create the Empathy Map based on the information collected. If that isn't possible before doing an Empathy Map exercise, the team should arrange to have representative users or even someone who knows them really well be interviewed during the exercise. It's also a good practice to have the team members mark each sticky note that they're not certain about with a question mark during the exercise which can then be followed up with some user research to explore or validate those areas of interest. You want to have confidence in the information captured in the Empathy Map in order to glean insights from it for your project. At IBM, we have a User Research practice that provides the foundation for our IBM Design Thinking framework.        
2. No Organizational Alignment. One of the tangible benefits of design thinking is the collaboration across diverse participants, diverging and converging, and creating a shared understanding of, alignment on, and commitment to the desired outcomes. Often key disciplines, organizations, and decision-makers are not included in the design thinking exercises. Those important voices therefore aren't heard and those people are excluded from the collaboration. All key disciplines, organizations, and decision-makers need to be included in the collaboration in order to achieve organizational alignment. Even if all the key players are included, teams sometimes don't diverge and converse properly. They will sometimes have the facilitator solicit input which then gets written on sticky notes. Other times, a senior participant will ask a junior member of the team to write their input on the sticky notes. Both of these approaches lack true divergence and convergence. The most effective way of ensuring input from all disciplines, organizations, and decision-makers present is to have them all quietly and individually capture their input on sticky notes (divergence) and then come together to share and decide on which of the collective input to pursue further (convergence). Lastly, organizational alignment requires that the team have a clear shared understanding of what was decided and a way to track the achievement of it. At IBM, we have teams develop what we call Hills, which are statements that say who will be able to do what with what wow experience. These Hills statements, a maximum of three per project, provide incredibly clear organizational alignment. Hills also provide the alignment function in Playbacks, which are meetings with all key stakeholders during which the evolving user experience is reviewed. Hills help to determine whether the objectives have been met. Organizational alignment is critical to the success of design thinking.
3. No Pervasive Use. The third and final major way that practitioners fail to use design thinking properly is when they fail to understand that it is a way of thinking that should be used throughout a project by all members of the team. Many people equate design thinking with simply doing a workshop. Some see it as a shiny new method that is in vogue at present and makes the team look modern. I contend that simply doing a design thinking workshop without follow through and use of the methods pervasively can do serious harm. An expectation is set after doing a workshop that if nothing happens and nothing changes then it is worse than not having held the workshop at all. If it isn't used pervasively, it can also lead to a conclusion by participants in a workshop that it doesn't really work. Design thinking, and IBM Design Thinking in particular, is amazingly powerful if it is practiced pervasively end-to-end on a project and by all key team members. Check out the IBM Design Thinking Framework for more information on the attributes and elements that are key to achieving optimal pervasive use. 

I've introduced IBM Design Thinking to hundreds of companies, practiced our version of design thinking on hundreds of projects, with thousands of people, and I've taught design thinking to hundreds of practitioners. I believe that the framework is amazingly powerful when used properly. As I've pointed out above, it can also be used incorrectly. I therefore believe that all design thinkers should take the Hippocratic Oath to "do no harm."