Comparator not powering blocks with short pulses

Comparators don't power blocks, when they recieve short (2gt) pulse. They seem to only power repeaters and comparators.

How to reproduce:Build the setup on the picture, then update the observers. Redstone lamp won't turn on in the left version, but will in the version on the right. If we replace observers with buttons or other long pulse versions, lamp turns on in both setups.