Thank you SFF_lib! I think you are right in that many amateurs play TT to kill time. I feel that if one is passionate about an endeavor, one may as well look to improve upon it. I think ttmonster, Der_Echte or NextLevel in the Daily Chit Chat Table Tennis thread mentioned "professional amateurs" - an amateur who is so into an activity, that they more than an amateur but not quite a professional.
I mainly play TT because it is fun for me. At 54 yrs old, I need to exercise regularly. I derive no pleasure from walking, jogging, etc. So for me those activities are "boring" and like a 'chore'. With TT, I find it fun as I played when I was a teenager and I don't think TT is a chore... so my mindset is not thinking "I'm exercising" but rather "I am having fun."
What better way to have MORE fun than to look to improve. Many of my club members are like you say looking to pass time, but there are a decent amount of ~USATT 1800+ members with that skill level looking to improve somewhat. For me, I really was playing like a USATT 1400 a few years ago, missing easy shots, not able block, attack, etc. So I am perhaps playing ~1500-1600 level now. I do not know if I will ever reach a 2000 skill level as I will not be playing tournaments, but I am striving to learn and improve. There is that old cliche about it's the journey and not the destination.
I have lost many a game/match in the past 3 or 4 years and many against players I should beat. I am my own worst enemy though, I rush my shots. A loss is not a loss if one can learn from them and look to improve. Slowly but surer I am.
Sometime ago, a friend mentioned I improved. I didn't want to believe her, but slowly, a few friends/members have also commented I improved. And now despite losses to some players/friends, i see the scores are closer whereas before there was a huge gap. My mentality is like that of a tribe. One member of the tribe looks to improve by helping the others in his tribe improve. As they say iron sharpen iron, if i improve this will help my partners improve also.
All I can say is to keep at it, one of my mantras: "Consistency trumps intensity." I have persevered somewhat and finally my hard work is paying off. Although upon reflection, if i had the funds and got regular coaching lessons, I would've probably improved much faster. But at this stage of my life, with 1 daughter in college, 2nd daughter starting college in Sept and my son will be in college in 2 yrs, I cannot afford to get regular lessons.
TL; DR version
1. Keep at it ... "Consistency trumps intensity."
2. "Iron sharpens iron." ... if i improve this will help my partners improve also
3. A loss is not a loss if one can reflect and learn from them.
Good luck in your TT training!