I have never sat in a circle with other graphic designers, held hands and burned sage while proclaiming Helvetica the perfect font. But I have worked with Helvetica as per my own graphic design projects. I have used Helvetica as per others brand guidelines too.
Helvetica is one of many good tools at the graphic designers disposal. It is just a clean, clear neutral font that comes in many weights. No font is perfect. No font works for every mood and can convey all tones and voice that the designed visual communication may need.
Some see Helvetica everywhere and they begin to hate it, others see this situation and appreciate it for at the very least for its utility, if not as Julie B. comments “Because Helvetica is da bomb.”
Not that many san-serif fonts can function well both as a display size and text size font. It can be modified fairly quickly, drawing by hand or with computer and software tools.
It is one of the fonts that made an early transition from metal to photo, then digital typesetting and to the desktop computer, so many university trained designers were exposed to Helvetica for the last thirty-five years in course work, then used it in professional work. Helvetica is well used in visual media and educated graphic designers know it on site. Even many laymen today recognize and know font Helvetica.
Helvetica is a font that's legible, and a favorite of many graphic designers for decades. Use it when or where it's appropriate.