Why won't the clinic show me other patients before and after photos? Should I be concerned?

I went for a consultation on sculptra and when i asked for before and after photos i was told their patients dont want anyone to know what theyve had done so they can't show me any photos. Is that right? I understand if patients don't want their before and afters posted on social media but why can't the clinicians show prospective patients their before and after photos? I thought it was a good question so I can see their work. Is this a normal reason or should I look for another provider? They're a pretty well respected and known clinic here where I live.