You know what else crashes servers? People. Goku, Vegeta, Gohan, Piccolo, Frieza, Cell, Krillin, and Buu tend to crash servers quite a bit. Ki blobs will do it... so will the dreaded kamehamehas. Final flashes too.... you know what? It's just unstable.
I've killed servers by detonating kamehamehas around too many team mates, by blowing up a server with a beam struggle, by smacking two spirit bombs together and letting them hit the wall. I haven't seen Gohan's shield ever crash a server per-se, and I've been in a server with more than one Piccolo without a problem (aside from the usual crashtasticness). Scatter shot seems buggy, but it is far from useless. Well... maybe not that far, but it is really fun to watching all those balls hit somebody after they are immobilized from a beam or something. Piccolo doesn't have too much to do aside from Beam Cannoning and using his uber eye lasers anyhow... someone using scattershot over and over is missing out.