You get to choose your intention. You don’t get to choose how it’s received. You were downvoted because people perceived you as negative, even if it’s not what you intended. Unless you have a better explanation?
What do you mean you didn’t say anything special? You called attention to something obvious. People normally only do that when they want to complain, i.e. “it’s monday” or “the bus is late” etc. If you want to call attention to something obvious but in a positive light, you have to say that explicitly, i.e. “it’s cool that there’s a lot of transgender people in the hacking community” or “nice, it’s raining!”. Neutral is negative by default, unfortunately.