Any sporting event, music concert or art show, from the amateur to the professional levels, would not be possible without the basic rules that make the uniting of people and discipline together in a venue that makes for either competition or entertainment. Oftentimes the basic rules are not always "out front" but without them sporting events, music concerts or art shows would not even be possible.
Such is the place of rubrics in the liturgy. The analogy here is not with sport, music or art in themselves but with the basic position and posture of those who are called to conduct the liturgy. The rubrics are not always evident and understood in the Mass. However, without these "basic rules" the pastor/priest and people do not have a sense of the place of God or their relationship with Him. Without rubrics, the liturgy does not flow gracefully as that place where prayer and proclamation and sacrament are united in action, just as God and people are united in Christ.
Rubrics, therefore, are not given as a legalistic ritual but are provided as a graceful discipline for the pastor/priest in his conduct of the liturgy.