Another (frankly more likely) possibility is that people think they deserve more recognition than they actually do. This post is based on the premise that it is the employer's fault and that doesn't necessarily follow.
Google has set up an environment that makes it pretty easy for people to transfer between groups, and even between sites. You have to be a grown-up about it, of course, and not ditch your team during some critical crunch time. But provided you exercise mature judgment in the matter, you can pretty much switch teams whenever you want, and it doesn't cause the company to grind to a halt, as such a policy would at other places I've worked or visited.
In our morning meetings, people update their status on the work they're doing. Even a simple "nice!" when warranted goes a long way, making them feel good in front of the group, and giving them a nice attitude for the rest of the day.
The asymmetry of the relationship makes it more likely for the employee to be get the short end of the stick. It's not inspiration and respect that get passed down the corporate ladder (in most companies). Many employees don't speak up for fear of repercussions (they are at the mercy of their managers, after all).