Because bitcoin is not physical, people have doubts about it. I totally understand your point, but in gold, you don't always have it physical manner, you can buy gold based assets from the stock markets as well. This way, I can't understand why some think bitcoin is untrusted. When an asset is not physical, this doesn't mean it's untrusted.
People doubt bitcoin not because of it got physical or not, but they believe that bitcoin won't survive for too long and afraid it can be banned by the government, while bitcoin is very profitable some people prefer gold to invest because it is more stable and will never being left behind by anyone, for now invest in bitcoin is very profitable and the enthusiasm for bitcoin is far greater than gold