Why is Mohammad Asad’s tafsir not recommended?

Muhammad Asad (2 July 1900 - 23 February 1992‎), born Leopold Weiss, was a journalist, traveler, writer, social critic, linguist, thinker, reformer, diplomat, political theorist, translator and scholar. Asad was one of the 20th century's most influential European Muslims.[1]

Muhammad Asad wrote some brilliant Islamic works in his early days including “Islam at the Crossroads” and “The Road to Mecca” which I highly recommend. However, in the latter part of his life, he developed some unislamic modernist ideas which he promotes in his translation/tafseer “The Message of the Qur’an” which includes a wrong understanding of Hijab and denial of the existence of the Jinn.

Dr. Yasir Qadhi says about his translation:

“His translation of the Qur’an, unfortunately, contains many unorthodox ideas. It is an English translation with a Mu'tazilee perspective. He denies the miracles that the prophets performed (for example, the resurrection of the birds in the story of Ibrahim, (2:260), believes that jinn are not separate creatures, and also has a very liberal approach to Fiqah (for example, the concept Hijab varies with time and place,cf. Surah Noor).

Apart from problems of this nature - they are numerous in number – English is one of the best that this author has seen; very lucid and readable. However,it is not to be recommended because of its misinterpretations.” [2]

References:

[1] Wikipedia: http://en.wikipedia.org/wiki/Muhammad_Asad

[2] Dr. Yasir Qadhi, An introduction to the sciences of the Qur’an, p. 372