Not just in trading but even in gambling too, you see people giving so much value and importance to bought strategies order than those ones they had to gradually build by themselves. And I see why. It's because the source from which they bought those strategies designate themselves to be professionals and expert in the niche and they get overrated and whatever they give out sells even though it still fails.
Perhaps if people can get to be patient with the strategies they are cultivating by themselves they can strengthen and understand it much better with bigger results flowing through than those they dare to buy.
It's due to lack of self confidence

Some traders are even more expert than those whom they get the strategy from but they have lost self confidence to trust their own strategy. I experienced same thing with gambling those days where we get games from others thinking they're better than us. We went as far as paying for games but still ended up losing before we realised they were not in any way better than us. When we play by ourselves, we win some and lose same. The same thing is applicable to trading here. Of course, there are people who are naturally better than us in this field but we must note that they're not absolutely wizard and their strategy can still fail us.