After all, there are actually people who "live" in these villages. The grocery stores, banks, and transportation to/from the villages can't be closed because the residents depend on them, too -
Been there in April. Except for one restaurant, everything in Mürren was closed. The lift from Gimmelwald to Mürren wasn't even operating. Not a single business was open in Gimmelwald. The residents who remained were mostly occupied with the tasks of preparing the pastures for grazing. And this involved fertilizing the ground with manure, sprayed through a power hose. The air smelled...um, quite ripe.
There was a little more activity in Lauterbrunnen, but not much. Interlaken was the only real center of life.