It's an extremely small selection, compared to what it was in the early 90's (that I remember - and I remember older folks complaining about how far it had gone down hill even then).
There just is no store I can wander around these days (or series of stores) where I can visualize exactly what I need to build some project. For example I needed recently to put some electronics in a waterproof outdoor box, and cable it up nice with proper waterproof conduit.
For someone who has done that sort of thing 500 times for work, you know exactly what to order and what everything is called and how it will fit. For someone who never has I really miss just being able to go to a hobby/electronics store and actually see the components I'd need to put something together - usually modifying my plans in the process as I see what is available I never knew existed before.
This makes "making things" really hard for the beginner and removes a ton of spontaneous "lets just figure it out and get it done" type of projects - at least for me. There is no store to run back to to swap out that $1.50 component I bought the wrong part number of. Minutes/hours of latency to days at best.
Electronics became disposable, TV repair went away, and the radio shack shifted.
I chatted with the sales clerk, who was on the younger side, that I should go back to school for electrical engineering, because that's the only way I'd learn the hobby. I bought an Arduino afterwards, but never used it. That encounter effectively killed it for me.
I'm an electrical engineer who develops hardware similar to the Arduino for a living. I'm still constantly amazed by the things my friends, mostly artists and web designers, make using Arduinos and Raspberry Pis. I remember buying one of the first Arduinos and thinking, "Why did I even go to school? They've made everything so much easier." My friends still ask me questions and help them troubleshoot things; but for the most part, there are tutorials and forums that often provide more information that I can. Sparkfun and Adafruit have a lot of great beginner level tutorials, but they also have some really complex and challenging projects too.
30 seconds found me this: http://www.aliexpress.com/item/Hot-New-Arrival-High-Quality-...
That shouldn't surprise you, RS employees have never had electronics knowledge. I forget the details, but as one example I remember a conversation while trying to get a replacement battery for a cordless phone for a friend of my girlfriend at the time (who is now my wife, meaning it was well over 20 years ago). Again, forget the details, but employee argued that it couldn't be the battery because "blah blah blah". It holds a charge for 34.6 seconds after charging it overnight and then has about 0.2V, what do you think the problem might be, oh Electronics Wizard?
Back when employees would at least try to pretend to be knowledgable, they'd argue with you if you made the mistake of letting them know what you're building. "You're building a FooBar? No, no, you need a WhatsaHoosit." You mean this article from a guy who forgets more about electronics than you and I will ever know is wrong?
EDIT: that said, when I went to buy some resistors a few weeks ago to fake a display on our headless Mac OS build server, a couple of bucks got me a card of five of them. So I don't know what is missing from supplying the "builders" market.