There are and should be doubts. There will be adversaries again probing for weakness and faults in the bitcoin, and now the LN protocols.
Meanwhile there is a huge and increasing lack of education and understanding on the protocol and the LN layer. In spite of the apparent slowness that we see in the implementation of LN, it seems that public understanding is not tracking with our technology but falls further behind.
Thus while we discuss issues with LN, BTC has just barely became something most or some people have heard of. Something that's vaguely like a stock. Maybe it's some magical internet money.
Is that gap between common understanding, and these technologies, increasing? Where does that lead?
Does it lead to some moment in which the common guy realizes there's a way he uses that bitcoin stuff to buy things with?
If so where is the technology by then?
Although I think that investors should have some decent knowledge about bitcoin technology, and this of course leads to some knowledge about segwit and LN (otherwise how will they decide to invest in bitcoin). I completely understand that it's users (and I'm separating users from investors here), won't have a great understanding on how it all works, and just want to be able to use BTC as a payment method it in a simple and easy manner.
I actually think that some of the bitcoins greatest problems to be solved, in order to get global adoption, will be related to how "common people", with no interest from tech stuff, will be able to use bitcoin. I mean, some people don't even know how to use windows well, and that's very user friendly. I know some old people that don't enjoy using debit cards, because they think it's to hard. Of course these might be extreme cases, but the gap you were mentioning will always exist, and it's perfectly normal.