No show at the national level can risk having their credibility ruined by ensuring one contestant is selected over another at this early stage. What do they have to gain? Stop all this conspiracy theories about "gambling" and "vote fixing", etc.
I think there is a simple reason for the results. First, there are way too many contestants in each round that are being disqualified (4 out of 7). This will naturally lead to bad results. Secondly, those from big cities have an inherent advantage over the others as they have a larger group of people who they know and who will support them. For example, if someone lives in a multi-story building, every person in that building would vote for him, additionally, people they know will be lobbied to vote for this particular contestant. I'm sure you've heard about "6 degress of separation", well it's all the more valid in large metros. This gives even not-so-good contestants a leg up at this early stage when the votes are being divided amongst multiple contestants who are not all that familiar to the viewing public. This explains why someone who is less talented from a larger city can garnish more votes than someone who is more talented from a smaller city. It's nothing more than that.
The main problem is that the current II system itself is flawed. You can't expect people to vote for 3 top contestants out of 7 and expect good results. It's unnatural. Now if the criteria was to eliminate one, you'd see much better results.