My grandfather did crosswords, my grandmother did 4000+ piece puzzles on her kitchen table, my great grandmother played dominoes with a passion.

These days we have video games to occupy a similar role. It's another way to pass the time and entertain oneself, like watching TV or movies, or reading, or whatever. You could even argue the additional benefit of active participation makes games a better way to keep entertained and mentally agile/active than something like TV.

Of course, it can be a problem if it consumes your life. Certainly an older person with a family should not be gaming the same way a delinquent high school or college student does. But as something to do an hour or two or three when there's nothing particularly important going on with your lives playing games is just fine, and I highly recommend it.

And some advice for you youngsters out there:

IMO, one of the worst things that can happen to people when they get older is to believe that what they enjoyed in their youth was lame or immature. I got rid of much of my toy and game collections when I graduated from college because I thought "it's time for me to grow up and be a man now." I've increasingly found myself regretting that decision, even to the point of buying stuff back (at much higher prices than I sold it unfortunately). You obviously shouldn't live in your youth when you get older, but there's no reason you shouldn't appreciate it and enjoy revisiting it from time to time and sharing it with your own children as they share their youth with you in return.