Probably yet another of a gigazillion bugs. If you preset does not contain keyframes, having some in there may trigger better behavior, but otherwise I'm not particulalrly optimistic...
I understand how to apply presets. It is necessary to use a double-click instead of dragging a preset to the layer.
Thanks for bringing this up. I verified the problem, we have a bug filed on the issue.
This problem also occurs when applying a preset to lights. (Cameras and lights are both special classes of layers.)
We will investigate a fix for a future release. Until then, please use the workaround of first selecting the target camera or light layer, then double-click on the preset in the Effects & Preset Panel, or use the Animation > Apply Animation Preset or Recent Animation Presets commands.
Apologies about the bug.