In Catholicism, why can deacons not celebrate all sacraments, but only Baptism (and Matrimony)?

According to [this post](http://canonlawmadeeasy.com/2013/09/26/what-can-and-cant-a-deacon-do/) by an expert in Canon Law, deacons can only celebrate the sacrament of Baptism and Matrimony. Similarly, Wikipedia states (apparently wrongly) that deacons can only celebrate baptism: >Deacons, like priests and bishops, are ordinary ministers of the sacrament of Baptism and can serve as the church's witness at the sacrament of Holy Matrimony, which the bride and groom administer to each other (though if the exchange of vows takes place in a wedding Mass, or Nuptial Mass, the Mass is celebrated by the priest and the deacon acts as another witness). Deacons may preside at funeral rites not involving a Mass (e.g., the final commendation at the gravesite or the reception of the body at a service in the funeral home), and may assist the priest at the Requiem Mass. They can preside over various services such as Benediction of the Blessed Sacrament, and they may give certain blessings. **They cannot hear confession and give absolution, anoint the sick, or celebrate Mass.** I went to the respective entries in the Canon Law (e.g. Mass celebration [here](http://www.vatican.va/archive/ENG1104/__P38.HTM)) , but they do not state **why** the restriction (as expected, since it is only law). I wonder which is the origin of these **restrictions**, i.e why the deacon **cannot** celebrate some sacraments. Is this part of the Tradition? I am particularly interested in the celebration of Mass. In fact, since deacons can be married, allowing deacons to celebrate Mass is a proxy for "married priests". This could perhaps be one of the reasons against it?