Try making eye contact with a Home Depot worker; in my experience they dart into the nearest aisle. Must be a crappy job - though it may be fun playing hide-and-seek all day.
I have never had a problem with the help at Home Depot, if I am looking for something usually the employee will stay with me until I have the part I am looking for and any questions answered.
That's probably because they require every employee to make contact with every customer they see. Impossible to get anything else done when you're doing your job in a store full of customers.
When they first started doing this I avoided going into Home Depot because I couldn't move a yard without some employee asking if he could help me.
I don't know where you've had your Home Depot experiences, but in W PA, I frequent several locations and have always found the employees to be friendly, helpful and courteous.
Not all of them are perfect, but maybe it's your glass, evil eye:)