BJP is just a little over Five years under Narendra Modi and Amit Shah and the party had already lost all of its reliable allies except for Akali Dal in Punjab. If the Saffron Party Leadership can blame anyone for this, it is none but Modi and Shah. It all started with TDP.
The cycle party with virtue of Development Orientation is a natural ally for BJP. We have see how they created a Magic in 2014 elections. With the greed to extend their sway in Andhra Pradesh, they suffocated Naidu by insulting him and depriving the State of all the promises they made during the elections.
Naidu, out of no options, even went to the extent of reaching out to Congress. BJP would never grow in AP and YSR Congress would never ally with BJP for Minority Votes. Then came Shiv Sena, the oldest and biggest ally of BJP. Sena is with BJP in the thick and thin. Moreover shares the Hindutva Ideology.
Sena went a bit extravagant in demanding 2.5 years term but Modi and Shah would not even want to negotiate. The result is that Sena for the first time in its history turned towards Congress and NCP. Despite turning to a Corrupt leader like Ajith Pawar, BJP lost one of the crucial states in the country. This new found habit of ditching reliable allies would definitely hurt BJP whenever they reach to the position of needing the help of the allies.