As an experienced professional pilot who has been "resting" for nearly 2 years now I would have no guilt about taking a job with the likes of Virgin or anyone else, knowing full well that I might return to aviaition at a later date.
Please tell me why this should be unethical.
It would, of course, be unethical to not tell the truth at interview should one be asked questions concerning future plans but we always tell the truth at interview, don't we?