There is no "good" reason to do this outside of "it's fun to watch the replay".
A TH 10 in my clan posted a raid he did where he got 450k G/500k E and 3.5k dark on another TH 10. He put a few barbs down by the TH and up popped 4 max teslas. He then went in from a different side and leveled all the storages. Ended up with a 1 start but 95% of the available loot.
The funny part is that at the start of the replay you could see some grave stones near the TH. This most likely meant that some lowbie "tried" to give him a free shield and failed. I bet he wished he had that shield after he got stomped.



