I think that there are a lot of happy people around the holidays, but I think there might be more unhappy people. The holidays can bring upon great sadness for people for various different reasons. Some might not miss their families. Some might not have any where to go. Winter is a hard enough time, but the holidays make it that much harder.
There are families that do not get together to celebrate because the were brought up that way. They in return to this, do not celebrate together or in fact celebrate any holidays together. Since, getting together to celebrate on holidays is not normal, it makes them depressed once the holidays come around. It makes them very depressed.
The economy is bad, so people can't afford to purchase everything for their loved ones. The holidays are also a time of reflection. When someone passes that you love, you no longer spend the holidays with them, and that can be very depressing. There are more people on anti-depressants than ever in history. Maybe we need to reevaulate what the holidays are all about!
People miss their families and can't get to them, they buy gifts they can't afford that the people getting them don't want because "that's what you do", every errand takes five times as long, and it's a mess. There's still some good to be had in the holidays, but it's overrun by a wildly out of control corporate mess that ruins a lot of it.
The holiday season (Thanksgiving and Christmas) has become so commercialized that people seem more completely detached from the true basic spirit of the holiday season its self. The existence of Black Friday is a nod to the fact that there is mass retail appeal for the holiday season. Mass retail appeal is not necessarily a bad thing, however, when you have people willing to spend hours waiting outside in line (as of this last holiday on Thanksgiving, not even on actual Black Friday) it could be argued that people are detached from the true holiday spirit and are therefore truly less content than in previous years.
A holiday can cause one to be happy since there is the true holiday spirit within the holidays. For example, during Thanksgiving, we celebrate to feel the true meaning of being thankful, and during Christmas, we feel the spirit and again, thankfulness. Even though there is no one to celebrate the holiday with, there is still yourself, or possibly your friends or even your pet. You need to think positive during the holidays, and that is what they are for.