Rating systems don't matter very much
The political news lately surrounding games has been about the California video game law being declared unconstitutional, and the Rhode Island AG working with the ESRB on an ad campaign in support of the rating system. As a developer and a parent, I am all in favor of the rating system for games: it solves some perception issues and satisfies most folks. But as a developer, I also know it's only secondarily important.
The ESRB's judgment about games is dwarfed by Walmart's judgment.
Walmart is influenced by the ESRB ratings, in that they won't carry "AO" (Adult Only) games, fullstop. Much like the fact that they won't carry "X" movies, Walmart rightly puts a lot of value in the perception that they're a family-friendly retailer, concerned about children and the influence games may have on them.
Walmart is the biggest game retailer in the US, and they have a huge influence on what goes into games. Like the rest of mainstream America, they give all but the goriest violence a pass, but anything remotely suggestive of the existence of sex is forbidden. Which is fine: who am I to argue with the company responsible for 8% of all US retail non-auto sales? The point is that, for all practical purposes, pleasing Bentonville is a lot more important than pleasing the ESRB. Walmart does its own assessments, and makes its own demands of game publishers, and these carry huge weight with all game makers.