Morality As a Limit
Intrinsicism is the belief that value is a non-relational characteristic of an object. This means that an object can be valuable or not, good or bad, without reference to who it is good or bad for, and without reference to the reason it is good or bad. A present day example of it is the belief that guns are evil. People claim that guns are evil in themselves.
The idea of intrinsic value is a rationalization. For morality to be useful, values must exist as absolutes. If values are subjective, then they are mere figments of imagination, and one cannot hold others to one's personal moral standards, since they are believed without reason. Intrinsic value attempts to solve this problem by creating absolutes that are always true. The value exists as a characteristic inherent in the object.
The notion of intrinsic value is false, though. By attempting to say the object has value regardless of context, it undercuts how we decide if an object is of value. Value is relational. To exist, it needs a valuer and a goal. We say that water is good because it is necessary to live. Too much water, in the form of a flood, can kill us. Water in that context is not valuable. But according to intrinsic value, it would still be, or water wouldn't be valuable ever.
Since value is said to exist as an aspect of the object, we need to answer the question of how we identify value. No scientist has ever detected this mystical quality called "value". In practice, since intrinsic value undercuts our method of identifying rationally what is a value, we are left with no objective method of discovering what is or isn't a value. We are left with identifying value with whatever feels right to us. This, though, is equivalent to subjective value.
Since the aim of the idea of intrinsic value is to make the value absolute (non-subjective), it fails miserably. The practitioners of this theory can only salvage it by referring to a supernatural power the confers value on the object. Whether this supernatural power is a god, or a non-intelligent force doesn't matter.
The real problem with intrinsic value is that it denies the need of an objective moral standard. Whatever moral standard is taken, it is not one's life. This means that the moral code will conflict with one's interests, and make life more difficult, if not impossible.