Nintendo then introduced the concept of locked down consoles as a way to control game quality.
http://www.ign.com/articles/2011/09/21/ten-facts-about-the-g...
> Sid Meier in 2008 cited the Seal of Quality as one of the three most important innovations in videogame history, as it helped set a standard for game quality that protected consumers from shovelware.
[1] https://en.wikipedia.org/wiki/Nintendo#Seal_of_Quality
[2] https://en.wikipedia.org/wiki/Shovelware#Shovelware_video_ga...
However you are correct, they did lock down future consoles with the intention of increasing quality of published games. The flipside is that Nintendo has few third-party AAA titles and the majority of their game hits are first-party Nintendo franchises. Nintendo commands a loyal fanbase though, which is hard to come by (especially since it spans multiple generations now).
Really makes me shiver :S
The effect of shitty shovelware is a little hard to describe when even the best games of the time are a blocky mess and can support only a handful of game mechanics before running out of space in the cart. The Atari 2600 was insanely limited and even relatively simple games like Space Invaders required near god level hacks to implement.
More likely consoles are locked down because:
1. Exploits may allow cheats in games, most worrying for multiplayer titles.
2. Exploits may allow unfair unlocking of achievements, which add to overall "gamer rank" systems.
3. Locking down the ecosystem ensures you pay the console tax to get your game on the system.
4. Locking down the ecosystem prevents game piracy, which is one of the very few advantages consoles have over PCs.
Edit: A surprising number of downvotes for claiming console makers care more about money than they do about their customers. Need I remind you that one of the only titles available for the PS4 on launch was a $50 port of Angry Birds?
Valve's anti-cheat seems to be merely OK and may have a false positive problem.