I have a penned a series of detailed vendor neutral posts regarding "Why do I need a water softener" and various other aspects of water softener(s), RO etc. Links to all these posts are listed towards end of this post. It is a very valid and 100% genuine thing that some people do not like water being too soft i.e., for their skin or general feel etc.
In this topic, I will try to cover few options that are available to address water being too soft along with the topic, does having water softener provide protection to appliances installed down stream? Water heater (tank based, tank less, geyser etc.) is one of the main appliances that commonly gets impacted due to the scales (hardness) in water. Scale build up could greatly reduce the performance of water heaters, potentially contribute to increase in utility bill and also shorten lifespan of water heater ( you can research on web and there are several YouTube video showing how scale deposits shorten the lifespan of water heaters and how bad it could get in some cases).
With other appliances like dishwasher, coffee maker, faucets, washer etc. while we see the signs (stains, whitish rings), the impact may not be anywhere near to how water heater gets impacted due to presence of scales (calcium and magnesium). As most of us know water heater replacement is expensive (average cost of basic unit being around $1.5K - 2k)! How often do we hear, I only installed my water heater 6-8 years back and it started leaking? My water heater made a loud sound or is makes noises, my water hear is leaking from the bottom etc. I remember recently few of the members posting videos on NextDoor about water heater making pop noise in their garage etc.
One of the primary reasons why water heater gets impacted is due to heat. More heat means, more calcium and magnesium getting separated from water molecules and depositing / settling down at the bottom. Heat enhances accumulation of scale build. The more water flows through the water heater the higher the quantity of scales deposited in the tank. That is the reason, scale build up generally is not that big of an issue on cold water lines! Again, am speaking in relative comparison and not in absolute terms. Of course, apart from choosing the water heater that self cleans , there are many options to slow down the scale deposits including lowering of the water heater temperature, replacing sacrificial anode rod periodically (every 2-3 years), installing water softener, reducing the quantity of hot water use, flushing water in heater tank every year etc.
But how many homeowners do these basic maintenance activities regularly? It is very rare that after the water heater has been installed, it is almost forgotten and assumed everything is fine until it suddenly gives up. The damage caused by scale deposits is over period of time, depends on several factors including how hard the water itself is, heat etc. So generally, you would not notice any decrease in performance or impact to appliances for several years until it suddenly becomes an issue. There are some water heater scale deposits cleaning options using chemicals such as Lye, De-liming chemicals, Vinegar and Hydrogen peroxide, but most of them involve very tedious and time consuming process and not ideal for every situation or for most.
Given all of the above, for whom softened water is an issue (which is fair and 100% valid concern), they possibly could consider softeners that allow you to control the softness level (there are some good ones for very reasonable price available in the open market) to meet your comfort or consider electro magnetic / magnetic de-scalers or whole house inline mechanical de-scaling filters (available in from some good brands for around $300 and requires filter change about every 6 years). All these options cost around $200-$400 for equipment and most can be self installed and if you are not into DIY, just factor in install costs as well i.e., for overall cost. Those who maybe interested in knowing electronic de-scalers, they could refer to the following post. Towards the end of the post also includes links to various other aspects of residential water purification. All vendor neutral and just sheer information on what actually happens.