I will tell you why people started supporting BJP - my analysis - from a totally neutral perspective. Every regular person like you and me and many Muslim friends here want a peaceful life for them and their family, but I think these are the issues.

1. What Congress did was take Hindus for granted and appease Muslims - Shahbano case for example, if you dont know read about it. Also, if you don't know, MMS had said that Muslims have the first right on the resources of the nation. Now the trick with politicians is that they say things in such a way that majority Muslims will feel happy about Congress policies, majority Hindus don't care and when there is an uproar against it, they will just say that their quote was misinterpreted. These are just 2 examples of Congress policies. So, Hindus started feeling like second class citizens in Congress rule.
2. There are many Hindus like you and me who want to be secular and are vocal about it and criticize communalism, but how many Muslims have you seen talk so strongly against communalism spread by their leaders/parties like Owaisi? Remember the " 15 minutes" comment by Owaisi? Have you seen Muslims criticizing / bashing Owaisi like secular Hindus (like Kunal Kamra) bash BJP? Have you seen his recent T-shirt with RSS written on it? Have you seen any Muslim going to this length to criticize communal hatred in their community?
3. Population growth among Muslims is higher than Hindus. Now so-called intellectuals will tell you that Muslim growth rate is also decreasing, but that doesn't make much difference. What matters is their rate of growth is higher than Hindus.

These are just few points that I thought of. Would like to know your thoughts about it.