What's wrong with the Roth point count?

Forty years ago two oustanding bridge players, Alvin Roth and Jeff
Rubens, wrote the book 'Modern Bridge Bidding Complete".
It featured the Roth Point count Method.

This method is similar to the British combination distributuin count. 
It is based on the standard Work  point count for HCP plus Goren's
short suit count of 1,2 and 3 for ddoubletons, singletons and voids
resp. but also adds points for suits longer than five cards.
Specifically it counts 1 pt for each card over five for any major suit
but counts such length points only for "good" minor suits having at
least two  of the top three honor cards. 

Has any r.g.b. member ever used this method and if so, what are its
shortcomngs? It specifically does not count quick tricks.Why is this
method never mentioned any more?

Stig Holmquist