Perhaps I didn't make my feelings clear. I they're charging incentives then that is their business. I very much doubt this is a easyJet policy but rather a local policy set up by the handler.
If someone does get charged however it is because their bag is too big. If I have to cram everything into one bag and pack cafefully, then why should someone else be allowed to bring their oversize bag onboard? It's not real fair is it?