You shouldn't be beating Crota only to get 3 radiant materials. Materials should either not drop be in his drop table at all, or the amount be increased to something more reasonable
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More materials means less of a grind, "getting to the fun part of gear" which is something I've heard Bungie realized might be turbo lame. Grind to get the gear, then grind to upgrade it. That's pretty stupid, especially when they artificially limit the materials you need to get those upgrades.