Not to mention that when mods get nerfed, changed, or new ones are introduced (the Stasis kickstart mods, for example), entire builds can be forced to change and that means you have to dump more mats into getting the right elements on multiple pieces of armor, often including that Exotic you're trying to build around.
The whole game forces you to grind endlessly just so you can even begin playing it, then once you settle on a build, you're forced to grind endlessly just to get the right weapons or prepare for a future "balance adjustment" that directly impacts what you're doing.
People don't really play Destiny anymore. You either spend more time in-game than you do at your job, or you're left behind.
EDIT: And that doesn't even take into account the upcoming changes to ability cooldowns and stat distribution. Some entire builds can be completely unusable once that goes live and you've gotta regrind all the armor all over again for different stats to compensate the changes.
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