Out of hundreds of people actively using the software a few are having problems, yes. Of course the people posting on the LFJ forum are going to be those having problems -- the ones it's working for will have little to say because they're too busy enjoying the results (though quite a few have posted about their success with it).
I am actively working at figuring out what makes certain setups and configurations not work for some people. But then others that were having problems posted realizing it was things like having their Windows Firewall allow the app to work.
When you have as many different setups as Windows allows, some people are bound to have problems with software, especially software that automates a browser and is constantly connected. That's just the reality of an extremely diverse software environment like Windows.
Again, I'm sorry it's not working for you, but I'd ask you to make sure you go through the LFJ forum and take all of the steps outlined (adding all of the sites to the Trusted Sites list, making sure that your Firewall and Antivirus software allows SM to do its work, etc).
And your feedback was that SM is a spam tool, which clearly it is not. It pins highly relevant images to people who have actively expressed an interest in your niche and have chosen to follow you. Nothing about that qualifies as spam.