Yes, it is true that BJP also buys crowds but I have attended a speech of their leader once and I was astonished to see that many people were genuinely interested. They were not bought or brought. So, BJP does this a bit less than others. Congress is particularly notorious in this and the erstwhile rallies and even a 'maha railla' in Patna during laloo's rule were worst. I once asked a guy in the procession what he was protesting / supporting. He didn't know what the issue was. He was promised 35 rupees and brought in a bus along with others from a remote village in Bihar. . Basically, as long as people are impressed with a 'show of strength', crowds will be bought. Also, many leaders are often exclaiming in front of the media that their leader pulls more crowds and other leaders fail in this. In order to prove this in this stupid game of oneupmanship, they resort to such tactics. The only show of strength should be the elections and nothing else.