If you read all the replies and conversation on those XUMM threads at their twitter account, it explains a lot.

In my limited understanding it isn't any problem with the ledger itself.

They said it was because all these developers pushing new tokens were using the two public nodes that are available to developers to access the XRP Ledger, when the terms for using those public nodes specify that they are not for production use.

The people pushing airdrops of new tokens should have set up their own nodes, is the message I was getting from what the XUMM twitter account was saying.