I think every author should be responsible his/her items and portfolio. Maybe the item will sell in 6 months better, who knows? And there are other aspects to care about like seasonal products and so on.
If you ask me, I dont want that envato is deleting my items. But I share the perspective to maintain a high quality portfolio.
I have some items that were never been sold, because the niche is too small but maybe one day someone is looking exactly for this item.