I'm going to try and keep this free from my own personal thoughts on the topic - very recently, I've watched a man mourn for his wife after 60-odd years of marriage. That anybody has the audacity to question this strikes me as ridiculous. Instead, I'm just going to throw this in for consideration:

Most women outlive their partners. In Australia, at least, the average age that men are expected to reach is 78.5 years. For females, it's 83.3 years. Also of particular interest in this discussion:

Quote
Of male deaths registered in 2005, 55.1% were in a registered marriage at the time of death, 18.7% were widowed and 14.8% were never married. In contrast, female deaths showed 26.6% were in a registered marriage, 56.5% were widowed and 8.9% never married. This difference is a consequence of the greater longevity of women.
[Source: Australian Bureau of Statistics ]

I'm sure you'd find similar statistics in other western countries.

Maybe the reason you're finding more about grieving widows is that there simply are more of them.

Dave

'I just kind of died for you;
You just kind of stared at me'
- Aurora, Foo Fighters