If the other side behaves honourably, I would completely agree with you. If somebody tries to screw me, than " I do unto them" as you English say
I understand that I could choose to simply spend my money elsewhere, but I see no moral obligation where my counterpart also sees none (remember the switched off DRM servers from Amazon).
If I am just a fiscal statement for a company, to be analyzed for potential profit and cut loose as soon as the profit margin drops ( without honouring an previous agreement), I reciprocate in kind...
kaas