No. Some things are self-evident.
Are they really? I don't know about you personally but I do know people who have just went ahead and helped only to find something buried and destroy it without knowing. Myself it was a small bench that was custom made and the property owner swiftly told me how much it cost him and wanted me to replace it! A friend of mine caught the edge of the paved surface which wasn't finished even to the gravel area and then wanted it fixed for free!
SO NO some things are not self evident and unless you are willing to ask then you wont get my help volunteered !
If your nieghbor wont ask my first assumption would be they don't need the help, my second assumption would be they would rather shovel than risk having me hit something buried or dig a little of their yard by accident and the hole offering of the help makes outlining any possible risks feel very weird. At least by asking when I then tell you that I could easily dig up some yard by accident and will not pay for it if I do, or crush anything your children may have left behind to be buried by the snow, or that the bicycle that is buried will cost me plenty if I find it with my blower and the repair will be on you I wont get looked as strangely
Todays world isn't the same as it was when I was young and simply being a good neighbor can easily cost you plenty more than its worth for the good feeling of just helping someone out. So for me if you don't ask don't expect me to just jump in and help you out!
So an other question comes to mind now We have a close by neighbor who has all his toys ATVs, snow mobiles, boat motorcycles. Problem is he lives out here with no real means to take care of his long driveway except fro shoveling it by hand. So do I offer to help by just going over and doing it while he plays all weekend with his boys on the snow mobiles? Or do I wait for him to ask for help being as he can afford all the toys he should have first afforded himself one NEED or even a small plow for the ATV to at least try to keep himself from being buried. This especially since the NEED for a plow on the ATV is definitely more important than a snow mobile. Secondly shouldn't he be teaching his children to clear the driveway first even if it is by hand long before they are left to go have fun with the snow mobile? I don't know about you but I don't want give those kids the impression that they can do what they want because the neighbor will take the time to bail you out!
Bottom line here is your neighbor doesn't always see what is self evident to you and even if he does he cant be sure exactly what your thinking so maybe you should stop relying on an old fashioned neighborly policy that simply cant exist in todays society of spoiled brats with a self sense of entitlement that are willing to blame you for anything that can possibly go wrong and in the future just walk on over and simply ask them if they can help!