Both lead ineluctably to physical death. Both involve the withdrawal of human intervention to prolong physical life. When that withdrawal occurs, death is inevitable.
You stated that you "made the decision to end chemotherapy and pursue hospice care only" -how did this end your wife's suffering?
She passed away and the suffering ended. Hospice care is solely palliative, i.e. pain reduction; it abandons all efforts to cure or extend life.
IMHO, your wife's situation was much different from Terri's. You make another excellent point referring to what happens in hospice care, and it is one of many reasons why Terri is improperly housed at a hospice. With that feeding tube, she is not terminal (as her five years there would also indicate). She does not receive antibiotic treatment for infections in hospice, as it is only palliative care given there. She did not receive regular dental cleanings and exams, because hospice only provides palliative care. Terri is not dying, and she should not be in hospice! Terri being housed in hospice for five years is only one of MANY irregularities in this case.
Well -according to your definition we are all intervening to prolong life when as parents we feed our infants that can not fend for themselves.
Chemotherapy may be extaordinary -feeding is not. Food, like oxygen is essential to life -intentionally taking either away is extraordinary (murder).