Difference between Unrealistic and Unviable

UNREALISTIC vs UNVIABLE: ADJECTIVE

Unfeasible, Unattainable, Unworkable, Realistic, Unachievable, Fantastic, Phantasmagoric, Phantasmagorical, Surrealistic, Kafkaesque, Surreal, False, Delusive, Chimerical, Unreasonable

Intolerable, Unrealistic, Impossible, Profitable, Infeasible, Unsuitable, Nonviable, Unsustainable, Unworkable, Unaffordable, Impractical, Viable, Untenable, Unprofitable, Unfeasible

Unfeasible, Unattainable, Unworkable, Realistic, Unachievable, Fantastic, Phantasmagoric, Phantasmagorical, Surrealistic, Kafkaesque, Surreal, False, Delusive, Chimerical, Unreasonable

Intolerable, Unrealistic, Impossible, Profitable, Infeasible, Unsuitable, Nonviable, Unsustainable, Unworkable, Unaffordable, Impractical, Viable, Untenable, Unprofitable, Unfeasible

Accept that this is totally unrealistic and vague.
That could lead to unrealistic estimates, he said.
Say no to insensitive, unnecessary and unrealistic demands.
Extremely unrealistic ending and extremely unrealistic character change for the main character just to fulfill the propagandistic agenda of the writer.
It is unrealistic to romanticize the difficulty of birthing, and equally unrealistic to traumatize the child by frightening him.
Regarding unrealistic comparative optimism, some evidence suggests that unrealistic comparative optimism can have more subtle and worrisome consequences.
This show did not start out unrealistic but has gotten progressively extremly unrealistic as it has gone to the point of being stupid.
It is wrong for the therapist to set unrealistic goals and demand that the patient undertake unrealistic tasks.
Fifth, do unrealistic absolute and unrealistic comparative optimism have different consequences?
Calling grading is unrealistic and metrics are unrealistic.

The highly possible need for yearly replacement or major repair makes it unviable.
EBRD to maintain market presence and client relationships in otherwise unviable markets.
Massive increases in Public Liability Insurance have however made the exercise unviable.
Falklands commercially unviable, thus the idea of such a service was dropped.
When projects prove unviable, public or government sponsored entities suffer losses.
We also allow aborting fetuses with genetic or unviable diseases.
This effectively rendered fox farming economically unviable in the country.
Crude oil produced making it economically unviable for ONGC.
Pakistan make them commercially unviable for private sector developers.
Did it turn into an unviable church of believers?