Thirdeye has a great site with good info on Bacon.
Instacure is a choice.
It will give the cured meat the distinctive pink color and texture. It also kills any baddies that could cause botulism or other food born illnesses. So, if you only salt cure, you should be extra careful in your prep and handling and you won't have the color or texture you may be used to. I'm not saying it's right or wrong, but just a choice. We were using regular salt and spices for thousands of years to preserve meat before pink salt was ever introduced.
This guy goes about meat preparation in more traditional ways without pink salt. Worth a look to check out.
I'm sure others will chime in, I'm certainly not an expert.