There is a very clear reason why we don’t keep seeds is piles just like that in real life. A lot of smaller critters (rats, mice and various insects) eat seeds if they are left unprotected (insects are small enough to get to the protected ones too). If the air is too humid mould and mildew also can spoil the seeds. It actually makes a lot of sense for the seeds to decay if not stored properly. If we have rotting food it is logical for the seeds to decay as well.
To be consistent, plant fiber should require drying before using it so it doesn’t rot.
Fun Fact: splitting the topic with my post as the first one made Discourse recognise me as founder of the thread and actually earned me a few Discourse badges 
Kudos to @Relyss but I don’t think that’s how it’s supposed to work so consider this a Discourse bug report.