So you played other people's music aka covers.
Composition (writing your own music) is just one skill of many in terms of potential skills a musician may possess. So basically it does not make you better or worse than other musicians if you write your own music just different. I could write music if wanted to but I don't enjoy doing it and don't find it rewarding therefore I don't.
Well you called it a downfall which is negative...
Also re: the first sentence... Saying you don't mean it as an insult and then delivering negativity doesn't negate the insult... For example, I could say something like "I don't mean this as an insult but you have a f'n enormous nose/arse etc lady..." Would you still be insulted if I said that despite prefacing with I don't mean it as an insult? I reckon you would