Yes they are. If the cat has been free to roam for all his life it's going to take a lot to turn him into an indoor creature.
I grew up in a rural area and I've seen this a lot. Cats are very low effort pets when you can let them out but they're not low effort pets when you keep them indoors where they don't get the stimulation of hunting and it's a much worse difference if you try to turn an outdoor cat into an indoor cat. We never had a shortage of stray cats around because people would keep making this mistake: they'd take an effortless outdoor cat indoors and get surprised by how much effort it takes to entertain an outdoors cat turned indoor cat.
Try caring about what's good for the animal instead of what's good for some cat haters. An outdoor cat does not instantly turn into an indoor cat unless very young. Some never do and then it's just cruelty to keep the animal inside meowing to go out.Anyone who tells you you should allow the animal to roam outside is giving you bad advice. Unless you can keep it on your property you're only making the lives of everyone else in the neighborhood worse.
It is perfectly normal for a cat to sleep all day. Cats are crepuscular which means they normally rest during the day and night and get active during the twilight hours of the evening and the morning. Pet cats often adjust to the routine of humans who give them food during the day but if they're following their instinctive rhythm they'll be asleep all day.
If you want to help this cat to adjust to indoor life you will need to substitute outdoor hunting with play time during the evening when he would want to go out and try to gently get him used to a different rhythm. If you always feed him during the day (instead of just keeping a full cup), for example, he'll get used to being active during the day and he's not going to want to be outside as much at midday.