Why was I down voted?

I was going through the platform this evening when I noticed my rating dropped by 2 percent. I waved it aside, I didn't know what it meant.

Later, I went to my profile and was checking my previous posts, all my upvotes were gone. I checked and realized that I was down voted.

I was downvoted by @adm and @spaminator .pls, I will like to know why this is so and what my offence is so I will take corrections.

My votes just went like that and it's sad.