I've still got a bit to go before I'm 60, but even at my age I've seen plenty of horrendous spells of form and managerial crises before, and for better or for worse we're still ticking along much the same as always. As they get older, a lot of folk also just have more important things in life to be passionate and/or upset about than how their football team's doing, especially these days. (Though I'm sure I also feel it less because I rarely get to any games any more.)
For some younger fans, how they feel about the current string of debacles will probably be on a par with the most frustrated/disgusted/angriest they've ever felt about anything, and that's absolutely fine... it would probably have made my blood boil 20 years ago too. But now I'm just too old for that sort of thing