I haven't personally experienced negative results from onlookers, friends, or family when I direct approach. I understand the fear but the reality is those fears just don't manifest or if they do they are extremely rare.
I think a lot of it has to do with how you present yourself. If you walk up to a girl and say, "DAMN GIRL! YOU ARE SO HOT!" or just act in a very aggressive, loud, predatory manner, then sure, you're going to have risk there. But if you approach a woman with a friendly smile, make solid eye contact with her with soft eyes, and politely say (without being over-enthusiastic or loud), "Excuse me, I know this is a bit unusual to just walk up to a complete stranger and start up a conversation, but I noticed you a moment ago, thought you were really cute, and I just wanted to meet you," you're likely to get a positive reaction from that, even if she isn't interested.
I know we all talk about how social media has ruined women by providing them with free, endless validation from thousands of simps, and I do believe that myself, however, I do know that when an attractive guy, who has the balls to walk up to a strange girl in real life and tell her she is cute and that he wants to meet her...... that is worth more than 100,000 likes on Instagram. While the likes provide her with validation, the real-life approach makes her experience much stronger emotions and physical sensations. Women are drawn to people who make them feel a certain way, and you are doing this in a cold approach.
I know some guys are averse to providing women with validation and therefore don't want to give her the compliment that results out of a direct approach. I get that, and in all situations aside from direct approach, I agree and I don't validate women either. The number of times I've liked any girl's photo on Instagram or FB or wherever is 0. But I've just found that direct approaches make more sense in certain situations. I like having both direct and indirect options available and well-practiced, so that I can apply them in any given situation.
Walking down the sidewalk and see a woman walk by me going the other way. What am I going to do? Think of something dumb to ask her like what time is it or ask for directions? Scenarios like this simply don't lend themselves well to indirect approaches. You aren't going to make conversation with a woman walking with a purpose. So the guys who don't do direct approaches would probably just let that opportunity go. Not me. The girl I dated before the last girl I just broke up with, she was 24 and I literally stopped her on the street, used the exact technique I described above, and we dated for a year and took several trips together. It works. Trust me.
Now if you are in the grocery store or certain other locations where the girl is a captive audience (like a girl waiting for the train and reading a book - you could start up conversation about the book she's reading), there are a lot more opportunities to strike up conversation and be indirect. But just remember, you ultimately have to get direct with her at some point in order to ask her to connect or ask her out so you aren't avoiding validating her, unless you decide you aren't interested in her after talking to her.
Lastly, I will say an additional benefit of direct approach is that not knowing what you really want from a woman makes her nervous. That CAN be a good thing, but only if she is interested in your looks at a moment's notice, is in the mood, and is available. It's awkward even for women to talk to strangers, even if they aren't the ones initiating, so if you just start up conversation, they usually assume you are attracted to them, but they are anxious because they aren't quite sure and they really just want you to get to the point. So I notice when I direct approach, most women kind of look at me with wide surprised eyes like "Oh my god what's happening now - is he going to serve me with a summons or is he a crazy person about to talk nonsense to me or ask me for money or or or" while I get my direct opening line out and as soon as I finish it, you can see this immediate change in their expression and their body. They shrink down, stop tensing their shoulders, stop holding their breath and exhale a bit like "WHEW" and then they start to smile from the flattery and they start up conversation.