I am sorry, it's unfortunate but there are people who set things up so that everyone comes to them for connections. Could be out of habit like I mentioned where your parents just got used to holding things at their home and hosting. (at least when it comes to family). Often that happens because otherwise it would mean having to make a choice of who's place to go to in order to celebrate and gather. And when it comes to family that is too sick to make the trip, often that is taken that these family members prefer to distance due to illness and should be excused and not imposed upon.

It sounds like your family simply doesn't know how to function any other way then what they consider the norm, their norm. People can be funny that way where everyone gets used to whatever the established norm is and they genuinely don't see it as an issue. People can get settled into a routine and just don't care to change.