Most non-trained photographers, and most "normal, regular people" are not very adept at spotting bad lighting, nor identifying the source of bad lighting as being either flash, or daylight. It takes some training to be able to readily identify lighting "issues". As one poster commented on earlier, even people who are learning photographic lighting often (all too often, unfortunately) make the mistake of using electronic flash that DIRECTLY OPPOSES "the sun", and looks utterly craptastic to a trained eye. I'm not referring to any photos in this thread, or to any person in this thread, but a few weeks back we had a poster who was using flash and compositing images in which the foreground people were lighted by flash, but the backgrounds were composited in and had strong, DIRECT shadows that went in the OPPOSITE direction as the shadows from the background. While other people let it slide, I felt compelled to mention it because...that looks really poor.
Most normal, regular, everyday people do not look at photos with any degree of knowledge of how they were lighted; they look at the images based on who is in the photos, and their own personal, emotional attachment to the people in the photos. Just because a client likes a photo or photo set does not in ANY WAY, mean that the photographic technique is "good", "great", or "fabulous"; it means that the PEOPLE in the photos evoke a positive reaction, for them, the viewer.
If flash will help the photos look a bit better, use flash. If you cannot hold the highlights and the shadows are pretty dark...you'll probably wanna use some kind of fill lighting...reflector fill or flash fill...or move...or use a scrim to diffuse the light and lower the lighting ratio so the images look,well, "better". How good the images look really depends more on the skill of the shooter than on which method is used. I've seen really fabulous fill-flash work and also reallyt bad fill-flash. Same with reflector fill--I've seen it look fabulous, as well as really drecky.
[note: I wrote this post before seeing Tirediron's post above; my post had nothing to do with the question he asked...]