His film wasn't any good to begin with
It wasn't about being "good" or "bad."
D'Souza is a Republican, a minority in the same "Ivy League establishment" that the President heralds from, education-wise. Despite common assumption, most of the established, heavy wealth tend to be very Democratic-leaning, focused on charity and philanthropy. You see similar in US voting, both PhDs and non-HSD/GED voting Democrat, while HSD/GED through Masters tend to vote Republican. First generation millionaires, usually not in the top 0.1%, but 0.2% down to 2% (make 5-6 figures, but saved/worth 7 figures around the top 1% and just below), voting Republican, while multi-generation millionaire families being Democratic.
Even the President himself has been very charitable. You often hear him talk about paying a lower tax rate v. his gross income than his secretary. Of course that's only because his net income is lower because he donates well into 6 figures of charity. But it's easy to pick apart gross income, not just for charity, but especially for someone self-employed or with a small business like a S-corporation, sole proprietorship, etc... when they have extensive expenses or other revenue that they never see as a result of running the business that is tied directly to their personal income.
Because so few Americans have ever handled the finances of a small business, they don't understand how someone can be in the bottom of the top 1%, yet bring home less than $50,000/year to live on. Most are not getting big write-offs for allegedly luxuries either. I've personally been there myself over several years, living on only 20% of what I made gross, because at least over 60% was direct expenses related to very unluxurious travel, basic business expenses and other costs.
D'Souza is also Indian. So his documentary puts forth his theory that the President approaches many policies from the standpoint as, what he feel is, anti-Imperialism. He feels that some views by the President, even different from most other Democrats in the Ivy League establishment, are not focused on existing US wealth not allegedly earned, but more aligned with the US being an Imperialist nation that has pillaged other nations, including great portions of the US as like "pillaged nations." It has merit, although I think D'Souza oversimplfies his argument, and fails to provide broad proof.
However, for those who have read the President's book about his father, it is rather disturbing the regard and views he holds directly from his father, who he knew so little of. That's why, before the President was elected, I never cared about any debates of whether he was a natural born American or of Islamic faith. My questions were always where the President got his values, especially having being a socialite elite, Ivy League and otherwise out-of-touch with a small business person. I held the same contempt for W. as well, just to be fair.
It was Obama's own voting in the state of Illinois that disturbed me the most, and carried over to the Affordable Care Act (ACA), especially the portions the US Supreme Court did rule Unconstitutional. The law stood, but several sections were changed, especially most sections where the 30-something US state attorneys, and not all from alleged Republican states that most of the media tried to paint as, where costs were increased for them. The US federal government had to take on the fiscal costs as a tax, and not use other methods to fund, such as via state revenues.
So while I think D'Souza failed to provide much evidence for his argument, the theory itself deserves more expansion. It does at least try to explain why the President has his views. So it's not so much anti-Obama as trying to explain Obama, even if it is clearly in a negative light from the standpoint of D'Souza. D'Souza is clearly relating to the same, general, negative regard of how many Indians hold the British, and how that sometimes drives negativity that is not productive for the good of India.