The way it works this time is fundamentally different. Last time (and all the times before that) the government asked "We'd like to buy F18 fighter jets for this much money, can we do that please?", and the swiss people said "yeah, sure!".
This time it started the same way, but the swiss people said "nope!". THen they were like huh, uhm, ok, looking at our data here there seems to have been a lot of very different reasons why people voted no. Some didn't like the plane proposed, some didn't think we need new fighters at all, some thought we'd be better off by not having a military in the first place, some just had some other gripes with some other decisions of ours and thought this was a relatively inconsequential way to kick us in the shin. If we just propose another plane the same is bound to happen, so let's reframe the question: Can we have a budget of 6 billion to buy new fighter jets? We'll decide which one by ourselves if we get the budget". And the swiss people said "yeah, ok" (juuuuust barely).
So with things being what they are and what was agreed on in that vote, there's not much that could be done to derail the decision. In that vote we gave the executive the budget and the full authority to decide which jet to buy, which they didn't have before.
Oh... OOOOOOOOH! That's the first reasonable explanation I've heard for that weird anomaly!! ?