I am in a similar situation: learned over 40 years ago, played very seldom and very casually until July. Took some online training and played a lot of chess. I've played more in the last 4 months than the previous 40 years combined. I've gotten a lot better AND I'm enjoying it much more not getting my butt kicked all the time! I'm up to the 1400 range in 4 months on here...not too bad for a beginner, and I honestly think I can continue to raise that with study and experience.
Does striving to improve diminish your enjoyment?

I feel myself on the other side of the fence regarding "why" I play chess. . . by the way, now only in Chess,com (I am 86, retired and enjoyng being tranquil at home)
I like chess for itself. . . like to play and study, and not precisely win games.
I used to play tournaments and rated games and came to be around 1500 But I got tired of the anxiety that may produce to be worrying about the "rating". . which will take me to nowhere
. . .So. to hell with ratings. .,now I am enjoying my (Internet) chess playing Unrated, and I think I improve something..
(Incidentally, in that way I have found more "foreigners" (not USA or UK) players. So far I have played 46 flags).

I don't only play for ratings, its just a measure of how I'm progressing/learning. I also like to play Chess 960 for the reasons you give; to enjoy and learn; and I could care less about my 960 rating.
Striving to improve is the source of my enjoyment. I prefer not to sit in the depths of ignorance. Ignorance is bliss for some but I will take enlightenment any day of the week.

Do you need to do some disciplined study to improve ? Certainly not (though it may help).
Do you need to put in some effort to improve after you've hit a wall ? Probably yes.
Do you need to improve to have fun with chess ? That's a personal question everybody must answer for himself, but nobody requires you to achieve any rating.
Playing a dull chess game diminishes your enjoyment, but that's because of you. Trying to improve is hard, but thats what makes it fun: what fun is any game that is easy?
Perhaps he just wants something to relax with in the evenings or whenever and nothing more from chess. Sometimes easy is better.
For over 40 years now I have played and studied chess off and on--sometimes passionately and sometimes not at all. But in all that time I have posted precious little improvement.
Unfortunately, every time I get excited about playing Chessmaster or Fritz, going back to the club, entering a tournament, buying a book--I immediately start thinking that "this is the time. This is the time I'm going to get serious and get better." But, at 61, I'm pretty sure that getting significantly better, i.e., going from 1200 to 1600 or above, just isn't in the cards without INTENSIVE study and training.
So my question is this: Do you find yourself enjoying chess less the more you strive for those extra rating points? Instead of playing over a master game (not bothering with the 10 move variations), solving some tactical problems, reading/studying a book simply because it's entertaining and well-written, do you think that a disciplined course of study is necessary in order to approach chess at all?
I'm beginning to think that I should just treat chess as I do crossword puzzles. I do a lot of them and have a lot of fun with them. But if they're too hard (like the Friday and Saturday NY Times puzzles), I just do what I can and then crumple it up. There's always another one that's easier and more fun. And I never obsess about getting a better puzzle rating; it's just for me and for fun.
Any thoughts?