he then mentions that Popper considers none of witt's ideas to be any good. (for some reason, Magee himself likes some of them). please note that in general Popper was very forgiving and lenient with bad philosophers (e.g. Kant, Hume, and Berkeley), so when he says Witt was worthless that is *very strong* condemnation.
oh wow, here is a strong quote p118
Since the later philosophy of Wittgenstein not only is not about philosophical problems in any traditional sense but denies their authentic existence, it is capable of appealing powerfully only to people who do not have philosophical problems. This explains two things about it that might otherwise be difficult to account for simultaneously: its great appeal to academic philosophers and its attractions for people outside philosophy.(Magee has talked earlier in the book about how many academic philosophers do not have philosophical problems)