Nope. I love working with my team but if a better offer or a more exciting project came along I'm outta here. I still am constantly applying to jobs around the sector.
loyalty and respect to your team doesn't mean sticking around in that position. It just means not screwing them by slacking off (when the work would fall on them) or snitching or scabbing etc
"Work ethic" for most wage slaves, is just being a good subservient worker bee that does whatever the boss tells them. It's a ridiculously vague term and your definition is not at all common sense. That's why I explicitly specified "to your colleagues".