I am not a fan of BJP and consider it a negetive force(may be a necessary evil, at best). However, the moderates within Hidutva brigade mostly emerged from BJP, and they have done a good job of controlling the rabid "hindutva" advocates.
Advani's resignation can be labelled irresponsible as it will bring forth more hardliners in the leadership. Result, same old - riots, bands, economic unstability and minority bashing. He and Vajpeyee were the middle path (if any such thing is possible in BJP). Though outwardly pitching on "Hindutva", at best they were nationalists in their policies.
After a decade of careful diplomacy, both BJP and Congress were on same page on Pakistan. The tensions have eased, people are softer and we can talk more progress and less military spend.
This resignation is a platform for Togadias, Modis and Thakereys to come out of their holes and make merry. Add to this political and economic uncertainty