Consequences for not attending an academic conference/forum in which your paper was already accepted? BACKGROUND

I was previously an engineering PhD student but I left the program.  I was really too inexperienced for the commitment of a PhD.  Further, my wife wanted me to leave and pursue an engineering job with a salary.

A while back I submitted an abstract to a relatively prestigious conference/forum, where the corresponding paper was suppose to be submitted 3 months after this acceptance.  Since I was leaving the program, I basically neglected this responsibility while applying for jobs throughout the semester.  However, my adviser expressed anger on this saying I must submit the paper because they already accepted the abstract and I could be barred from the forum in the future.  Thus I submitted a paper.

As of now I've left the PhD program.  However, there is a conference/forum for this paper in the upcoming week, and there is a speaking slot for my paper.  I know that my advisor (the paper's only other author) is busy and overseas and will not attend.  This means nobody plans to attend the conference for the paper.  Thus, I feel I must attend the conference.  However, I really don't have the funds and time, and cannot easily attend.  I checked the schedule, and there is a speaking slot for my paper.

QUESTIONS

What are the consequences for not attending an academic conference (for your accepted paper) in which you are slotted to speak?  I would assume not attending (complete absence) is common due to money and air travel problems (connecting flights, weather, etc). Would one be barred from future conferences for not attending?  Is it impolite to not attend (I've already successfully submitted the paper)?
It is unlikely there would be any consequences for failing to present at a conference.  It would be impolite and disappoint your former adviser.  You should notify the conference if you decide not to attend.