I for one do not like the cartoony style modern logos are trending towards. If you look at some old helmet styles like ours, or the old patriot one with the actual patriot on it, it looked simple and gritty. When you draw a dolphin with a snarl it just looks silly to me. While this is an exageration, why not draw a dolphin with a machine gun smoking a ciagr slapping some girl on the rump? It just doesn't suit imo.
I don't mind restyled helmets like the Chargers who keep the same simple design but tweak it a bit and change the colors a shade or two.
When you think of the classic teams, Dallas, Pitt, Miami, you don't see alot of logo changes, because not alot needs changed. There is only one reason to change it, and that is for an unsuccessful franchise to increase revenues on newer logos, and try to reimage itself. The Pats were not that successful so they changed their logo around that time.