A quote from this text which I am still reading. This paragraph of Nikolas Kompridis sums up my understanding of the basic flaw of Habermas's critique of Heidegger.

"In my view, Habermas has wasted much of his critical energy driving Heidegger's undertaking forcefully but inaccurately into the aporiai of the philosophy of consciousness: the aporiai of Heidegger's thought are not the aporiai of the philosophy of consciousness. A much more valuable and fruitful encounter between Habermas and Heidegger would have explored the advantages and disadvantages of their respective paradigms of intersubjectivity, paradigms whose respective disadvantages could be corrected through mutual enlargement. If he had treated Heidegger as a proponent of an alternative paradigm of intersubjectivity Habermas's attempt to probe the shortcomings of Heidegger's early and late philosophy would have yielded more persuasive critical results. He could have argued more effectively in support of his claims concerning the moral and political shortcomings of Heidegger's philosophy if he had identified the most glaring weakness of Heidegger's approach not as the lack of a properly intersubjective starting point but as the lack of a sufficiently developed account of intersubjective accountability and recognition."

Why? Because the strong Habermas interpretation is actually a misreading of Being and Time, as it is based on a subjectivistic/monological reading of that text. That text can be persuasively interpreted as an attempt to break out of the subject-centred paradigm of modern philosophy and to move away from subject-centredness towards intersubjectivity.