That’s like saying food availability is a core component in the obesity epidemic. I suppose there is some truth in that, but the solution it suggests is wholly inadequate.
For example, it might make sense to restrict the availability of very high-calorie, low-nutrition foods like fast food, or tax them to raise their price and/or subsidize healthy food. It would make sense to educate people about nutrition and exercise and healthy eating.
This kind of thinking could easily hold for the gun control conversation. Let people buy guns if they want, but not the really unnecessarily dangerous ones, and only one at a time. An 18 year old walks into your gun shop and wants to buy two powerful rifles. Why? What do you want them for? Why do you need two? These are valid questions.