If someone is acting suspicious, that is a completely different thing. Of course if someone is acting in a suspicous manner, the cops are going to approach them. We are talking about cops looking at someones appearance, and then determining what kind of person they are and/or whether or not they'll search them, pull them over, etc.
I understand what your saying, but if someone can't afford to dress nice, commonsense has nothing to do with it. They wear what they have and thats it. Of course, theres always those ones who dress and act that way because they want to be that way and want people to think they are "gangsta". Which, in my opinion, is ridiculous.
This isn't about whether people can afford to dress "nice". This is about people dressing like "gangstas" on purpose. I don't know about where you live, but a package of plain white t-shirts and plain straight leg blue jeans are far cheaper than the articles of clothing I'd consider to be "gangsta" style are. I don't consider someone in regular t-shirt/jeans to be suspicous. The people I would be referring to are the one's with their super baggy jeans (that they can't seem to keep on their butts), their caps, and their "bling" (whether it's real or plastic doesn't matter). If you dress like that, you get moved to the "potential for danger" category. No matter what you say, appearance DOES affect people's reactions to a person.
For example, if you saw one of these "thugs", and a well-dressed business man, which do you think would be more likely to rob a liquor store? (If you know nothing about them except their appearence.) And there's no real point in saying one shouldn't judge based on appearances, because everyone does it subconsciously.
Does that mean there are no bad cops? No. Does that mean that all people who dress like that are bad? Certainly not. Is it likely that being suspicious of a person based on their appearance has saved their life/enabled them to bring in a wanted person? Definately.
In short: bad police are still bad; good police are still good; profiling does help protect them from potentially dangerous people.