I've never heard that before. I had my first baby at 36 and my second at 40. My first was induced at 42+2 (not an experience I would recommend) but my second was all natural, no intervention at all and whadda ya know, DD came out fine . My mother gave birth to me when she was 39 and her mother had her last baby when she was 43.
It is my opinion that many doctors/obs like to do c/sections because they feel they are more in control. What makes me angry is that suggestions such as this can compromise a woman's belief that she can and will birth her baby naturally.
If the baby is all healthy then what do you want? That's what counts.