is there a reason to take indirect spells? Options

[Roy Fokker]

as a new gm with only two games under my belt, rules changes from 2nd edition (my last regular experience in SR) still astound me. last game i could have tpk'ed the party with an medium threat npc force/magic 5 manaball but luckily i messed up the rules and let them roll reaction versus it (and gave the caster cover penalties) in addition to resisting it with willpower+counterspelling. according to the rules, it's not a ranged attack to use a direct spell so you only roll magic + spellcasting vs body/willpower + counterspelling. is there a reason to ever use indirect spells other than for specific elemental effects? (i.e. the enemy is holed up near a 50gal drum of gasoline and you cast flamethrower) i could understand if you didn't add net hits to the DV but you do even in this case. on the flip side, how do you defend as a mundane against direct spells other than having a group member with maxed out counterspelling within LOS?

signed,
hoping not to be a killer gm (unless the group really deserves it!)