The point of a workshop is to generally meet with other people and talk about your work with them.
For that reason, workshops with peer-reviewed papers typically expect all authors to appear to present their work---even more so than is typically the case for conferences. In many cases, it is in fact strictly required, and papers will be officially unaccepted and removed from the proceedings if nobody appears to give the talk (IEEE, for example, requires this of all of their sponsored meetings).
In certain extenuating circumstances, such as illness or visa problems, some organizers may be willing to arrange for a talk to be given remotely. Likewise, larger meetings in some cases will offer scholarships that can help with the expense of attendance. If you just don't want to go, however, then you should submit to a journal rather than a workshop or conference.