I am not sure how you think this would ever be possible.

1 - Blockstream took a bunch of VC money and will need to somehow turn a profit. The LN is their only "product" therefore LN must somehow generate revenue for blockstream

2 - Even if the above were untrue, there must be some mechanism to keep track of who is owed how much in the LN and whoever keeps track of this is not going to do this for free (in Bitcoin the miners do this via confirming transactions and extending the blockchain, and in return they get the block subsidy plus the tx fees)