I worked there in the late 90's and did very well since I had a F'ing clue about electronics.
Fast forward to 2014 and I go to my local RS and the kid behind the counter was shocked that I went into the parts drawers and understood what a resister even was...
He said "I never even look in there, I don't understand any of this stuff..."
I feel it has a great deal to do with the people working there that have negative amounts of product knowledge (in the 90's they would train basic electronics to the noobs) and prob the largest portion, the internet.
BUT having somebody that knows a diode, resistor, or FET by sight would go a long way keeping people coming back for these type of purchases instead of running to the internet - IMO.