Yes, canned and otherwise processed food does have a ton of salt in it, as do many restaurant meals. One of the main reasons is that salt is a flavor enhanser. Foods that are mostly precooked and then preserved by freezing and canning tend to lose thier flavor, so the processors add salt to beef up the taste. KCl doesn't have the same effect. Not that I'm defending them, just explaining the reasons.
Over the years consumer demand has greatly increased the number of foods available in "reduced" or "salt free" versions and every time I go to the store I see more. Abby is quite right that processors respond to the bottom dollar much more readily than legislative action. And consumers are getting smarted and demanding better products, so slowly but surely the wheels are turning in the right direction.
Now that you are aware of the whole sodium issue, you to are better equipped to make good choices. The more fresh foods you buy and prepare yourself, the less sodium you will be consuming. Scanning the nutrient panel before buying prepared foods will not only guide your sodium choices, but fats and the unpronouncable chemicals added too.
As an odd turn of the issue, I actually have a hard time getting enough sodium. It is an essential nutrient required to keep your muscles firing correctly. Since I am an avid runner, biker, etc (kinda obvious, I guess) I sweat a lot, thus losing sodium. And since I eat mostly fresh foods, rarely fast food and seldom prepackaged food, I find myself supplementing my diet w/ sodium. Generally that's a good thing until you cramp up so badly you collapse on the trail
which happened during a race last year.