I was reading this paper by West, in which it is argued that:

Eleven dimensional supergravity can be described by a non-linear realisation based on the group $E\left(11\right)$

From which they conjecture that $ E\left(11\right) $ can be related to M-theory, too. This seems rather weird to me, given that $E\left(11\right) $ is a rather unwieldy group, given that it has a cartan determinant of $-2$. The cartan matrix of the group is as follows:

$$\left[ {\begin{array}{*{20}{c}} 2&{ - 1}&{}&{}&{}&{}&{}&{}&{}&{}&{} \\ { - 1}&2&{ - 1}&{}&{}&{}&{}&{}&{}&{}&{} \\ {}&{ - 1}&2&{ - 1}&{}&{}&{}&{}&{}&{}&{ - 1} \\ {}&{}&{ - 1}&2&{ - 1}&{}&{}&{}&{}&{}&{} \\ {}&{}&{}&{ - 1}&2&{ - 1}&{}&{}&{}&{}&{} \\ {}&{}&{}&{}&{ - 1}&2&{ - 1}&{}&{}&{}&{} \\ {}&{}&{}&{}&{}&{ - 1}&2&{ - 1}&{}&{}&{} \\ {}&{}&{}&{}&{}&{}&{ - 1}&2&{ - 1}&{}&{} \\ {}&{}&{}&{}&{}&{}&{}&{ - 1}&2&{ - 1}&{} \\ {}&{}&{}&{}&{}&{}&{}&{}&{ - 1}&2&{} \\ {}&{}&{ - 1}&{}&{}&{}&{}&{}&{}&{}&2 \end{array}} \right]$$

So, is this paper well-accepted in the string community?