My local retro game store also has the GB "bucket." Many games as low as $2. I love it.
As far as popularity goes... I was playing a lot of Nintendo back in the 90s: the NES / SNES / Game Boy era... To myself, and everyone else it seems, the Game Boy was the back-up and travel system. No one played it at home. They played it in a car, bus, hotel, whatever. With AA batteries and no backlight it just wasn't convenient to play regularly and it was pretty much understood that the home consoles had "better" games anyway.
Later on there was the Pokémon explosion on GB / GBC. This, combined with Pikachu Virtual Pets and Tamagotchi, made handhelds look like kiddie stuff.
Now we've reached a point where, I believe, the handhelds have actually surpassed home systems in terms of overall game quality and variety. If I want to play a modern game I gravitate towards the DS / PSP / 3DS / Vita over anything else. And the tech is now solid too - lit screens and rechargeable batteries.
Looking back at the original Game Boy from here in 2015... It's a great system. Tons of hidden gems. Even some intriguing imports. But I think some of the old stigma remains. I see "regular" folks locally still buying NES / SNES / Genesis games, but the GB carts remain on shelves. More for me I suppose.
Nintendork666 wrote:After all you can play these games anywhere, even on your television.
The layperson or very casual retro gamer might not even be aware of this (or the backwards compatibility of later systems, for that matter).