i too, have noticed this kind of jaded attitude from people, and yes, a majority of them seem to be in the "over 40" category. but i didn't notice this until i came to cc. maybe i was oblivious to it, or maybe having folks so clearly identified by their age group, it became more noticeable.
last year, i was getting to know a guy who was a good handful of years younger than me, and he was the one who actually brought this trend to my attention. he told me that he was worried that, upon getting to know me, he'd find me to be bitter, and have a negative outlook on men and relationships. i remember how hard i laughed at this comment, because the correlation between age and "bitterness" struck me as so very absurd.
i think some folks become angry at the situation they are in, or feel too hopeless to make the changes necessary to have different circumstances. as to comments about feeling as though my age has prejudiced me against love, happiness, or relationships of any kind --i've never ever felt that way. i have prayed for a long time that God would bring love in my life, and prepare me for it (as well as prepare him) and i have always believed that i would someday have that, or that if i didn't, God would be sufficient in His mercy and help me to deal with that outcome as well.
i think what age HAS done is show me how much i've taken for granted, and how much has been taken from me that i never thought might be. how so much that i assumed would always be there, or be easy hasn't proven to be the case. and the other thing i've found is that anything i've had any pride in, even a small pocket of has been taken from me, either permanently or for a season. that has been hard to accept.
honestly, i don't know why some are jaded and some are not. i will say, i have been very surprised by how many christians seem so very pessimistic, but i don't know whether that is related to age, or the individual--or that people will call things "positive" just because they ended their sentence with a smiley face. but i actually am more optimistic, happy and hopeful that i have ever been at any stage in my life.
and the best i can do is attribute it to the following:
1) i can't ignore the fact that i've been blessed with a personality (ENPF) that tends to lean towards the ideals, the glass is half full, and longs for the lighthearted, the joy, and the inspiration in life. also, strives for the authentic and real, what is true vs the veneer of saccharine or fake, honesty and growth vs. status quo and telling/hearing what appeals to our basic nature.
also, that it deeply desires to seek inspiration from all kinds of sources, and delights in encouraging and inspiring others.
2) i've worked hard to overcome a lot. i have talked about it here (to a certain extent) but some is more difficult to be open about--lots of childhood abuse and neglect, dysfunctional or lacking parental/family relationships, nomadic lifestyle and its fallout, sexual assault, destructive habits, addiction, etc. as a result, i've spent a lot of years doing the work to develop health and wholeness. i have found a lot of meaning and purpose in my life by seeing how God has used a number of events and circumstances to bring about qualities in me, and to help others.
there has been incredible satisfaction and purpose having the opportunity to help or encourage others that i have been given a heart for. usually my own life's events have led me to experience, gain insight or a develop a heart for people who are struggling or suffering. for example, i have always had a heart for the disenfranchised and those on "the fringes".
3) God has done a lot of work in my heart and life, and that has been the biggest difference of all. after my "trifecta" over 10 years ago (which was the three big life events, all occurring inside of 17 months--my grandparents death 11 months apart, my car accident and my sexual assault) the walls of my heart toppled over and it paved the way for God to really rebuild my heart in a new way.
in some important ways, i've changed quite a bit, something that has cost me friends, gained others, and created some significant shifts in what i value, what i long for, and who i've become today.
from that stubborn, independent, and prideful person came someone with a lot more humility, awareness of frailty, hunger for God, and above all, a fountain of joy in my heart that i'd never known. before then, i'd experienced happiness, but never really JOY.
today, i have joy that is independent of my circumstances, and sometimes it feels like a huge, fast-flowing river of joy that i can't help but feel overwhelmed by, and gratitude that often brings me to tears. which is another really annoying change that happened--tears. i never used to cry, EVER. now, i can be like another kind of fountain, which sometimes i find really embarrassing--usually just tears of joy.
it's not to say that i don't have problems and struggles, because i do. but i feel like the joy and gratitude seems to make these something that aren't insurmountable, and i have the faith that God has good in store for me, even when it doesn't resemble the outcome that i expected.