My SO has finger nails your length, except hers are filed in the pointier style. She's not in retail plus she is middle aged, so the vast majority of people that we know who do notice, keep their opinions to themselves.
One of my friends once asked my SO, while a group of us were sitting together at a restaurant, if my SO played the guitar. It was obvious that she was trying to find out why my SO's fingernails were so long. My SO simply looked her straight in the eyes and said, "No". I do think that more people notice as you say, and maybe the more intuitive people put two and two together. But, no one can control this and if you like long fingernails and you don't mind the possibility of having people wonder, just enjoy your nails!
It's a trade-off and only you can determine what is most important to you. My SO's nails are more important to her than what people may or may not think and this is her prerogative.