anti-social nerd gamers

Well there are those that add people to beg and other annoying things so a private profile may help with that, also you can make private only to non friends wich makes more sense, but it does look fishy to see a private profile. But tottaly their right, it's an obvious featuere I supose.

There are people who don't wish any relationships with the community, they simply wish to have access to their games.

Where is the strange thing?

Some just want to be left alone ... I used to have a private profile myself.

Smaller chance that other private profile adds you to make a scam.
I have a friend that has priv profile just because of this. Not sure if it works though :P

Just people just want Steam to buy games. Nothing else. Or they don't want to be bothered by other people and just stick with the real life friends that they are already have.

trolls and flamers

Cg has a private profile. And I highly doubt that he is a cheater/scammer/whatever. :P

I don't like private profiles either. I hope steam just removes that feature altogether, because too many scammers and bots got comfy using it. Not that I would fall for that, but a lot of other people will.

secret trade agents who have lot to hide !

My guess is casual gamers who just want to log in for a bit and play their games in peace, without being bothered by chat and random requests.

They dont want you to notice them senpai :3

I got it for friends visible only. Otherwise random people are adding me and begging for games or cards.

Becase they don't want to be bothered, because other people/scammers/whatever see they have a lots of games/playhours in certain games/lots of items/etc and maybe they can scam you/hack you/whatever.

I only accept invites from people I know for sure and they know me either.

Private profiles doesn't mean that person has something to hide. On the contrary. They want to stay hidden...

Sometimes it's personal. Like when you know a certain someone is "stalking" you online and you don't necessarily want them to see what you're doing and when you're doing it. I've set my profile to friends only before for this very reason.

Some people just tend to use Steam platform for gaming instead of having any social interaction with others or the community. I see nothing wrong with that.
You don't owe your privacy to anyone

I really couldn't care less who looks at my profile, or the reasons people keep theirs private. I find the responses here interesting though.

You keep it private because social interaction in real life is more important than on Steam? These two things have nothing to do with eachother. Almost sounds like you're overcompensating for something. I'm going to guess that you spend a lot of your free time on Steam, playing games, instead of being more productive and you're a little ashamed of it. So keeping your profile private just keeps the facade going.

You keep it private because you're afraid of being stalked? Just who are you, why are you so important and why does the universe revolve around you?

The only real reasons that I'm seeing are that you own a lot of games/inventory items and you're tired of people adding you and begging for stuff... and/or you've legitimately had issues with stalkers/harassment in the past and are doing it for your own safety. Pretty much everything else is paranoia, shame and/or overcompensation. Which is absolutely fine, how you conduct yourself online is your own business, but tell it like it is. Don't act like you're just "above" having a public profile.

I've mine set to friends only, this way I don't get bothered by random beggars/friend requests.

1. i never get invites from scammers or other unwanted people

2. why should i make more informations public that necessary?

3. whats the benefit of a public profile?

4. i have no need for social interactions with random people or "friends" i do not know

5. steam ist just a tool for buying/managing my games, works fine with private profile

Why not? It's a matter of choice.

Sometimes i put my profile to Private, when i'm playing DOTA 2. the profile in steam and in the game. Sometimes i put it to friends only. Don't want random (most of the time noobs sneaking around.) i meant noobs bcuz they see us playing and start sending friends request...

Some people had bad experiences on social network sites and don't wish for an encore. Some people want personal space. There are a lot of possible reasons.