Can you elaborate? Which part do you find to be bullshit? The Gallup research or Marx's thoughts? Both?
Marx was one of the greatest bullshit artists of all time, in that on the surface his writings sound intelligent but a deeper examination reveals that his opinions are based on incorrect premises which then lead to untenable conclusions. His opinions simply misstate reality.
For example, let's take just the first two sentences of the quote you posted:
"Religion is, indeed, the self-consciousness and self-esteem of man who has either not yet won through to himself, or has already lost himself again."
In the continuous flow of being or living in this world, man does not "win through to himself" or "lost himself again"; he simply reacts to the world around him with winning or losing, coping without putting a "win or lose" judgment on every little thing that happens. What can appear to be a win (e.g winning a lottery and then getting all kinds of unexpected problems) is not always a win later on, and a loss (e.g. losing a girlfriend only to find someone better later on) is actually a win. We simply do not know. However, we do not go thru life stamping "win/loss" judgments on everything we do - we react, reflect and focus on what is next all in a continuous flow. In real life, there is no such thing as a pure "win" or pure "loss", as there are further ramifications that muddy the waters. In truth, there is some good and some bad in everything we do and winning or losing is not the best way to describe our existence.
and then this doozy: "But man is no abstract being squatting outside the world."
Actually, the opposite is true: man is an abstract being squatting inside the world. What separates homo sapiens sapiens from every other life form on earth is consciousness: the ability to create abstract thoughts about his physical and temporal world.
I admit "religion is the opium of people" is a catchy phrase and sounds good, but as someone who has smoked opium, i can tell you they are two quite different things.