I think the overall presentation you put out to customers, should always, first and foremost, come off as professional. For instance, if you dress in a uniform, wear a company shirt and shorts/pants, but you smoke while on a property or are cussing or anything of that nature, it would come off as non-professional, even if you do outstanding work. People want the whole package. Polite, curtious, well mannered, hard workers that look like they know what they're doing will get more jobs.
If Bob, has an old riding mower in his truck bed with a new sign that says Bob's Mowing, and is driving down the road smoking as he goes not in a uniform, while Tim, has a trailer, a walk behind, a ZTR, Trimmer Racks and Blowers on it, plus has a uniform and isn't smoking, who do you think looks more professional?
Now Bob may do an amazing job, but just from the looks of it, and without seeing the lawns either have done, I would chose Tim because he looks more professional, he looks like he's more legit. He may cost more but his presentation is by far better than Bob's. You have to accept that people watch you at every part of the day you are out and about. If you make yourself look professional and act it, your more likely to get jobs from anyone looking for lawn care. Bob may only get jobs from people who don't mind smoking and who don't mind the lack in professionalism. It just how life is.