In all fairness to the brethren across the United States, but the Super Bowl has become something of an unofficial holiday in our country. Adjusting the church calendar to reflect this reality is not sinful or worldly. It's just practical, and a realization that people have lives outside of punching their church attendance clock. They like to have fun, and to have fun in the context of family, friends, coworkers, and other church people, outside of a formal church service or small group meeting. It's no different than adjusting the church calendar for other major holidays.
I think canceling all of Saturday night services is a bit excessive, and would definitely raise an eyebrow with me if my church did it. But dang... a church that normally has a Saturday night service. How many churches do you know that normally do that? Why the condemnation for this?
Perhaps the amount of volunteers needed during such a time suddenly become in short supply, and instead of brow beating people to show up and to volunteer and to come to church, that local church just realizes that getting together simply won't be practically possible. So instead of half-way doing a service with the few people they know will show up, they just decide to take off. What's wrong with that?
Additionally, while I am all for the brethren frequently getting together, and all the more as the day of the Lord draws near, I also realize that there are some times where many sincere and godly Bible believing Christians would rather do something besides attend another church service. Heck, in my own life, there are some Sunday mornings where I realize the best church I can go to is "Bedside" Baptist.
As somebody who has been active in ministry for over a decade now, I realize there are times where having a service is very difficult to pull off. For example, leading a small group between Thanksgiving and the middle of January is almost impossible. People are too busy with family, friends, and coworkers doing holiday stuff. As a result, I would suggest to anybody thinking of leading a small group in their area, that they should consider not doing so between Thanksgiving and Martin Luther King Jr holidays. If they do, they should think outside the box and make a style of meeting that will be a bit more festive and light hearted. And they should probably only do so on a bi-weekly basis, as people just won't be able to commit.
Most years I use the Super Bowl as a time to simply hang out with family and friends, and to enjoy some pretty awesome food. I've often thrown Super Bowl parties at my place. Church people often come. It's fantastic. I've used it as a tool to help build community around me. I put my hospitality gifts to use. It is something people have truly loved.
Of course during these times, you are welcome to host regular weekly Bible studies at the home of one of the brethren, or some other location, if you wish. But don't be so shocked if nobody comes, or perhaps only one or two come. For years I tried to have Bible studies during the Christmas holiday season, and often I found myself being the only one that would show up... and my groups really loved the Lord. At first I had a righteous and holy fit over these things. But then I decided it was much better to show grace instead. I've realized having another "church service" is not always the most profitable thing to do, and that people have lives outside of church related activity that is perfectly healthy.