This also occurs on bedrock, see MCPE-186248. The main reason why this can be particularly problematic is that it can kill your pets if your build happens to have a skylight consisting of glass blocks. If the interior of your house is also made of wood, this could lead to it burning down, too.

Steps to reproduce:

1. Give yourself a trident and enchant it with channeling.
2. Set the weather to "thunder".
3. Build a glass platform and spawn any mob underneath it.
4. Hit the mob by throwing your trident.

Observed results:
Lightning will strike the mob, and may end up killing it.

Expected results:
Lightning should not be able to pass through glass blocks. This behavior is inconsistent with the likes of other transparent/translucent blocks.