You nailed the correct wording in your question - "we become accustomed to". We tend to get used to and like what we become accustomed to.
For the same reason that we get used to overly salty things, we can get used to less salty things. What we get used to becomes normal and what we like.
I've experienced the salt reduction due to a health condition my husband has. We can no longer tolerate food with the same level of salt that we used to eat. By reducing the amount we use, we became accustomed to food with less salt.
I did the same thing with sugar in tea and coffee many years ago. I grew up with Southern style (very) sweet tea. I didn't gradually reduce it but cut it out all the way. To this day I don't use sugar in coffee or tea, add it to cereal (or buy frosted cereal) and I find many sweet things just too sweet for my taste.
I also liken this to learning to like new foods. There are many things I've tried and didn't like up front but, after continuing to try them, eventually found that I had learned to like these foods. One, for example is cilantro. When I first started tasting it I couldn't stand it. I swore that it tasted like soap. But after a while, I found myself really liking it. So much so, that I started adding it to many foods that ordinarily I wouldn't have thought to.
While taste is subjective, we can become accustomed to new things and often times need to.