During adoption, there will be a fee in the form of the on chain transaction to stake your coins and open a channel? So basically we are asking the userbase to endure a one time "adoption fee" in the name of lowering overall fees long term. When lightning network is operational, and transactions are largely off chain, then the on chain demand is reduced creating the fee reduction. That seems to be the biggest barrier to adoption, the requirement for "paying a fee to reduce fees".
Not everyone is going to suddenly start using LN at the same time. Some people will suck it up and be the first people to open a channel and pay higher fees. As their transactions move off chain, the fee will decrease, and more people will then join. That will happen so on and so forth; the fee will decrease gradually as more people use LN and more people will begin using LN as it becomes more widely accepted and the barrier to entry (i.e. the funding transaction's transaction fee) decreases.