Let's do an exercise. I won't ask you to write anything down, but make a mental note.

How tall are you? How much do you weigh? Where do you normally walk (city streets, gravel etc)?

Now let's say I'm selling shoes and you need a pair. You have 2 options. The first pair is designed for everyone. The second one is designed exactly for people your height and weight, and for walking on terrains you normally walk on. The price is the same. Which pair will you buy? No doubt about it, right?

This is why you have to state who your product or service is for, and it has to be true. If you're trying to sell to everybody, you will lose (unless you have a gazillion dollars to spend). Talking to everybody in your copy works for almost nobody.