Comment by Lynn Hunt;
Because the nature of what is erotic is fluid, early definitions of the term attempted to conceive eroticism as some form of sensual or romantic love or as the human sex drive (libido); for example. 

However, because eroticism is wholly dependent on the viewer’s culture and personal tastes pertaining to what, exactly, defines the erotic, critics have often confused eroticism with pornography, going so far as to say: “[Eroticism] is simply high-class pornography; better produced, better conceived, better executed, better packaged, designed for a better class of consumer.”

This confusion, as Lynn Hunt writes, “demonstrate the difficulty of drawing…a clear generic demarcation between the erotic and the pornographic”: indeed arguably “the history of the separation of pornography from eroticism…remains to be written

The Tech article tended to use the words interchangeably, erotica and pornography are very different. 
Pornographic film has as its primary purpose the graphic depiction of sexually explicit scenes. It generally depicts these scenes in a way that is degrading to women or, less frequently, to men. 
It tends to perpetuate the myth that rape and sexual assault are appropriate and acceptable forms of behavior. Erotica, on the other hand, seeks to tell a story that involves sexual themes. Sexually explicit scenes in these films serve a secondary role to the plot. Erotic film displays sexually explicit scenes in a more realistic and equal fashion that is not degrading to either gender

Pornography, commonly defined as “the explicit description or exhibition of sexual activity in literature, films, photography, and so on, intended to stimulate erotic rather than aesthetic or emotional feelings”. Current debate about pornography tends to divide along two main axes: the pornography/erotica distinction, and the issue of censorship.
commentary by conscious life style;
I believe that Erotic (Eroticism) is a good energy, but the problem that we have in our society today is that; this energy (desire of sexual passion) can be miss represented if the person who is overwelmed by Erotic energies is not well educated concerning the subject of sex.
Today the picture of what we call romance and intimacy, love and the act of sexual behaviour among human beings has been projected and imaged into our conscious via porngraphy, violence, prostitution, rape, child molesting, women abuse etc. 
I believe that due to the industry of pornography and the exposal of women as sexual objects, this is the reason why Erotic has become to mean the same as thing porngraphy to most of the people.