We should remove the dust limit from Bitcoin. Five reasons:

1) it's not our business what outputs people want to create

2) dust outputs can be used in various authentication/delegation smart contracts

3) dust sized htlcs in lightning (https://bitcoin.stackexchange.com/questions/46730/can-you-send-amounts-that-would-typically-be-considered-dust-through-the-light) force channels to operate in a semi-trusted mode which has implications (AFAIU) for the regulatory classification of channels in various jurisdictions; agnostic treatment of fund transfers would simplify this (like getting a 0.01 cent dividend check in the mail)

4) thinly divisible colored coin protocols might make use of sats as value markers for transactions.

5) should we ever do confidential transactions we can't prevent it without compromising privacy / allowed transfers

The main reasons I'm aware of not allow dust creation is that:

1) dust is spam

2) dust fingerprinting attacks

1 is (IMO) not valid given the 5 reasons above, and 2 is preventable by well behaved wallets to not redeem outputs that cost more in fees than they are worth.

cheers,

jeremy