Note: all videos were found on YouTube. If any need to be removed then just leave a comment and the desired video(s) will be removed.
Visually, the scene of ECW fans throwing chairs into the ring was considering shocking & compelling to TV & video viewers alike. From the promotion's perspective, it likely was scary due to the risk of injury as well as potential for fines (or even outright venue bans) hurting the company financially.
Regarding both ends of the spectrum, luckily it wasn't done too often; and this gave a special sense of rarity to whenever it happened.
Here are some other video clips besides the most well-known incident of ECW fans tossing chairs into the ring during and after matches:
