On the one hand, there are people who prefer for every decision to be made for them. If it's a group of men claiming to be god's direct channel, and they do all of the heavy lifting (interpreting the Bible, behavioral rules, general guidance), that is good enough for these individuals.
On the other hand, there are so many people who chafe at not being able to develop relationships with "worldly" people. Especially when it is so onerous that you realize you are looking bad, such as not taking part in a charity drive or other helpful community activity. Or not observing holidays to such a degree that you respond to "Merry Christmas" by either offering a flat "thank you" or pretending you did not hear them. I think there is a part of us that feels left out socially, and that hurts because we are social creatures.
The WTS may be afraid that allowing the rank-and-file to develop normal friendships and observe common activities will weaken them, but I think they are wrong.