I feel like a lot of the points raised here have already been raised multiple times in the Google Group in the past. I’m not sure how helpful it is to bring the old threads back up, but I’m also not sure how productive it is to rant again and again about the same issues.
Here are some threads I found quickly: 1, 2, 3, 4, 5
There are a bunch of separate issues that all contribute to the frustration, for most of which there is a related suggestion on the forum: students motivated by grades, duplicates, multiple photos of the same organism uploaded as separate observations (combining photos during submission is not super intuitive in the app or the website, but the new tool mentioned here will hopefully help a bit for after the fact), the user not adding any ID, and large amounts of (mostly) useless pet and potted plant observations. I think the last one is probably the hardest to deal with.