Why do fans assume loyalty plays any part in contracts, they are doing a job and want to make as much as they can while able too, as we all do in our daily life. Also what we offered in wages were obviously not as much or as good in add ons as that what Motherwell offered, even with the relocation in play.
In football i don't look for morals, hero's or role models they are the just doing a job and would move if the money gives them stability after they finish. Unless you are of a certain age these things will bother you, if you are older its all business and most should understand and not get worked up over the reality of the game today.