I don’t know that all automated writing analysis software is a scam. I also don’t know that no Nigerian prince has ever tried to give a foreigner 4 million dollars, but I know that most of it is a scam. Thing is, even if it’s not a scam, is it worth it?
I guess it comes down to why you decided to be a writer. If you decided to write because you wanted to make a lot of money, well, you’re probably not going to make a lot of money, and if the software works you should probably invest in it. If you decided to be a writer because you wanted to tell stories, because you love stories, then maybe you should trust yourself. Not that you shouldn’t refine your craft, become a better writer, but if you are just letting a piece of software decide how you should be writing, maybe you aren’t really a writer. Maybe you are in it for the money.
Let me tell you a secret: writing is hard work, just like anything else, and it takes either phenomenal luck or a lot of perseverance to make money at it. There are many, many easier paths to wealth, and many many easier paths to fame. If you are willing to let software dictate your writing, do something else.
On the other hand, there are tools you can use to help your writing. Expresso is one I found recently. It’s free. It does an analysis of your writing, and finds areas that might be issues (or might not be, your style has a lot of influence on that). You get to decide whether or not those are real issues, and you decide if you want to do something about them. Useful things are analysis of most used words, repeated nouns, things like that.
Basically, write. Don’t let someone sell you software that’s going to make you a marketable writer, because it won’t, and if it did, you aren’t a real writer anymore.