You analyze this situation in isolation
It is not about if people can or cannot learn something (they sure can if properly motivated). The question is basically about choice, not learning as such. If they can use web wallets and they don't need to install some abstract MS Office, the process which they likely don't consider as worth the effort, they will most likely choose the first option. I'm heavily inclined to think that if there were no web wallets, many people wouldn't use Bitcoin at all
For me web wallets and banks are not necessarily the same thing.
Giving people a choice is not always a good idea. We teach our kids math in school, because if given the choice most would rather play outside. But those kids would have a big problem later in life. So sometimes it is ok to force someone to learn something, but this is just my opinion. I think if you ask somebody if he is glad that he was forced to learn math or the use of desktop wallets, then most would agree.
Obviously, we are not talking about kids
But the assumption that giving adult people choice is not always a good idea itself works against your own considerations. First, who is to decide what is best and what is not, what is to be chosen and what is to be abandoned? Second, I could just as well claim that giving people choice in respect to which money to use (fiat or Bitcoin) is a bad idea on its own as well, and they should just stick to fiat (then see first). And last but certainly not least, isn't Bitcoin itself all about having choice?
I feel like a deal with kids all the time in the crypto world.
I imagine that we gave children choices at the beginning, but they fucked it up so bad, that we decided it would be better to give them rules. And what is the best sign that someone has become an adult? They break our rules, because they see a better way that goes against the rules and still decide to break the rule and make a new and better one. In my opinion this is why we call Bitcoin a revolution!
The difference is abysmal
In fact, you may feel whatever you might want to feel, but it doesn't matter. The difference that I'm talking about is that adults bear full responsibility for their actions and the consequences of these actions while kids don't (their parents and legal guardians do). In this way, your reference to Bitcoin users as kids which should be guarded is inconsequential at best. In other words, if you choose to treat these users as kids, you should also accept responsibility for their actions and financial losses incurred therewith
Adults bear full responsibility for their actions. How do you become an adult? Over night, just by turning 18. Why not 17 or 19? There is no reason you could present that will be convincing. No biological, no psychological, no whatever. Some are quicker at the point where they could be called responsible, some never. Someone just decided that it should be 18. It is just a rule made by humans and it is not always the right one.
So beside this problem i obviously do not talk about real children. It is more like the children are all the people living in a nation. That does not matter as there are also rules, or call them Law if you prefer that, for adults. Some of them are to protect others, some are rules on how to behave and there are also rules just to protect the individual from making something stupid that would result in unnecessary hardship or worse.
Sure we could give everybody full freedom of choice. In Bitcoin and in life, but for many this would end bad and i am also sure that the first thing that would happen is that we would start to look and use new rules one can live by. This is just a world i do not want to live in.
By the way there are two types of consequences. A direct and natural one. If i cut my finder of, then it is gone and nobody can take the consequences of not having a finger for me. The other one is more complex one. In case some damage is done and it is of financial nature, then a consequence could be to reinstate the damage. This is something that someone could take over and do for you. But it is a common misconception, that parents are financially responsible for the damages there kids have done. This is a complex matter and depends on the law of your country, but unless i support or do not stop the wrong doings of my children i am not responsible for it.