I didn't say there exist non-appropriate financial transactions.
So what is your problem with Counterparty, which is designed to carry financial transactions (but, in the mode of all such inventions, could be used for other stuff as well)?
I didn't say I have a problem with Counterparty.
Counterparty said it had a problem with what I and others consider to be reasonable limits, without explaining why (from what I've seen so far).
The 40 byte limit is very much arbitrary, and both Bitcoin and Counterparty would benefit if it were raised back to 80 bytes, because then we could store Counterparty transaction data more easily, elegantly and cleanly in the Bitcoin blockchain than we are doing now. 40 bytes is not just enough for our (legitimate!) use case. Of course, 80 bytes, too, is arbitrary, and the best solution is just to scale the fee with the amount of data so that the incentives all line up.
Where is the BIP explaining what the 80 bytes are used for and why 80 bytes are needed?
Reminder: transaction fees
do not pay for transactions, merely attempt to deter/rate limit flooding. To cover the cost of transactions, transaction fees would need to be much higher and somehow distributed across all full nodes (not merely miners).
I don't think that a BIP for this change is strictly necessary, given that there was none for the proposals to allow 80-byte OP_RETURN, or for the later change to 40-byte OP_RETURN.
A larger OP_RETURN space would allow it to support all extant Counterparty message types. We really need 80 bytes minimum, as the protocol was designed around that value.