The lawn mower is not a business. It is a piece of machinery. The business that designed the lawn mower can ensure the design is safe, at least within reason, through the proper engineering of the product and by instructing its users on the proper use and maintenance of the machine. There is nothing inherently unethical about manufacturing lawnmowers unless you consider the practice of mowing lawns unethical (which there are legitimate arguments for, but I don't think that was your point).
this seems a bit besides my point, but perhaps i am not as deeply into this topic as you. how about the baker at the end of the street. making bread for people, selling it at a profit margin which just allows him/her to continue their work as a non super rich person. (replace baker with barber or whatever). i dont see this as unethical. am i wrong?
Former baker here. There are still plenty of ethical dilemmas in baking: fossil fuel consumption in transportation of ingredients, factory farming of ingredients, if you are employing anybody you are paying them an unfair wage in order to turn a profit. There are inescapable ethical dilemmas of participating in capitalism. Success always comes at the expense of someone else. If you are a small business then you are less accountable to laws designed to protect workers than a multinational corporation.
Whether or not you deem the viewpoint useful, these ethical dilemmas exist. Whether you choose to acknowledge those dilemmas is your choice. But by recognizing these ethical dilemmas we can make better choices to reduce potential negative impact on others/the community/ourselves. Recognizing inescapable complicity is just accepting accountability and introduce the possibility to grow and change as individuals and as a society as a whole over time.
I don't think for example capitalism is always dilemmas. If someone choses to work for you, they chose to accept such a salary and participate. Its not some bad thing. If you truly pay them an unfair wage, they can chose not to participate. This might sound harsh, but people always have a choice. I work for an employer, i don't think its unfair simply because my boss is turning a profit. I am happy and thankful i have the job. If i didn't want it, there's plenty of space in the rainforest to try and forage for food (and yes i wouldn't last a day :P).
You might not like something, but does it really make it a dilemma in the sense of 'having to pick which of the 2 bulls horns will impale you?' - i don't think so. (interesting points though, and perhaps i am still missing your point!)