We've reached a point where the terms "gaming" and "gamer" are just too broad. Too many people play games regularly these days. Eight years ago, Blockbuster got blowback from gamers for trying to stereotype. While its ad campaign (below) was intentionally far-fetched, it was seen as insulting by the gamer population at the time. But there was a general gamer population to target. This is no longer the case.
Everyone and their mothers play video games -- literally. Grandmothers too. A recent study on video game correlations with violence in teens found that playing video games is such a common activity among teens that NOT playing games is actually an indicator of antisocial behavior among teenagers.
The term 'gaming' is now akin to the terms 'video' or 'Internet'. It's simply a content distinction. It might be on a PC, a mobile phone, or a TV. Trying to specify the user base with the term 'gamer' is like talking about 'video watchers' or 'Internet users.'
There is a problem here. The core gamer population, to whom the term used to apply, has a certain cultural identity around the activity which the recently expanded populations do not. The core audience reads and watches videos about upcoming releases. There are memes that populate among the core gaming population. If you've even heard about something called Minecraft recently, you're part of this group.
The challenge is that our lexicon doesn't differentiate between the broad group of "gamers," and this core group of "game enthusiasts." While game marketers know the difference well and their marketing tactics indicate this (casual game marketing targets the individual, core game marketing targets the community), many general brands find it a difficult space to wrap their heads around. And as social and casual games expand, the line between core and casual blurs. Up until recently we differentiated by calling the groups "core gamers" and "casual gamers." But causal gamers play nearly as often and as long as core gamers, and most core gamers also play casual or social games.
It's not a catastrophic issue, but it is worth keeping in mind. Personally, I try to dispel the myths associated with a term whenever I introduce it to an audience unfamiliar with gaming. Some audiences need to expand their concept of gamer from males 12-34 to, well, everyone. Others need to understand that while almost all demographics are gamers, only a portion self-identify as such. All around, we need better catchphrases for the general public to latch onto, or we're working at a disadvantage.