The VW was designed to be a cheap car. That windshield washer was a cheap solution.
Those silly Germans!
Not so silly. They included a valve in their system so that it would stop working before the spare tire was drained to the point at which it wouldn't be safe to use.
It was better than the washer in an English car that I once had. There was a little pump on the dashboard. Each time you pumped it, a little dribble of washer fluid came out. Most of it ended up on the hood rather than the windshield.
The German gas heaters were very effective and safe as long as they were maintained properly.
Of course, a lot of people never bother with maintenance.