That really isn't a valid argument... I'm fairly sure that at least 90% of people who use the internet every single day have ZERO knowledge of TCP/IP, HTTP(S), SSL and other technologies underpinning the internet... and yet they're able to post selfies and pictures of their cats/grandchildren without too much issue. 
That's because they don't need it. But how do you make sure you won't be charged an on-chain fee while you're paying for your coffee? You really need to be knowing how it works and be able to select what you want. Quote
You mention "huge fees"... exactly where are these "huge fees"... last time I looked, there are transactions getting confirmed with 2 sats/byte fees... OMG... outrageous! /s 
Sure, fees have been ridiculous in the past... but that was because the mempool was flooded and the whole supply/demand thing kicks off. Now imagine that the vast majority of those transactions are no longer in the mempool and are shifted "off chain" onto the LN... what is likely to happen supply/demand-wise then?
Less on-chain transactions = less "demand"/same "supply" = lower fees... That's kind of the whole point of LN.
Sure, fees have been ridiculous in the past... but that was because the mempool was flooded and the whole supply/demand thing kicks off. Now imagine that the vast majority of those transactions are no longer in the mempool and are shifted "off chain" onto the LN... what is likely to happen supply/demand-wise then?
Less on-chain transactions = less "demand"/same "supply" = lower fees... That's kind of the whole point of LN.
Bitcoin transactions have been declining big time. We're now at 187k daily transactions while there where 500k transactions not too long ago and the bitcoin fee was $65. Mind you, even 500k transaction per day is pretty much nothing world wide, VISA processes 150 million per day for example. Now imagine that bitcoin ever becomes popular. You probably can't use LN for payments over $100 dollar or it will become difficult already to find a route, so you're doomed to on-chain payment (or open a channel and also pay the on-chain fee). Now imagine what the on-chain fees will be if even 5 million on chain payments per day take place ? Probably hundreds of dollars!
*EDIT* LOL what am I even talking about, 5 million on-chain payments per day is impossible, bitcoin only supports maximum 600k payments/day !!