It's way, way, way too soon to judge the long-term implications of Meltdown and Spectre on Intel. If their clients want to switch, it'll take months and years to do that. That doesn't mean they won't do it, but it means we won't really know the full extent for a while.
The stock price is a really crude metric. For judging the long-term implications of this, we can't look at how the stock has performed in the last two weeks alone and extract any meaningful information.
My prediction: nobody big is going to switch away from Intel entirely, but they will start to prioritize investments in technology built on its competitors, as a way to hedge their future risk. That's definitely bad for Intel, because over time, it'll reduce their lock-in.