Religiosity is ridiculous, but then my view of religion is pretty different than others'. While most people consider religion any sort of belief pertaining to their worldview or that sort of thing, the connotative use for religion most of the time seems like what is being described in the OP: A sort of social club that people take advantage of and rub in other peoples' faces. It ends up being something very negative and that's the last thing Christianity should be imo
But let's not limit this to Christianity, there are plenty of other belief systems- and even lack of belief systems that have lots of people who act the same way. I know plenty of non-Christians who bash the beliefs of others and then act like they're the ones under fire.
And besides, it really depends on where you live. Here in the Bible belt (especially in a small town like mine) nearly 99% of everyone is a Christian (or at least say they are) and look at atheists like they have three horns on their head and should be burned at the stake. While down in Florida, where I lived previously, most people still claimed to be Christian, but there was more than an equal amount of atheists, agnostics, Muslims, etc. Here our Christian club is thriving, in Florida it didn't even have enough people to continue. Where I went to school there I wouldn't be surprised at all if it felt like Christianity was a dieing philosophy