I guess the problem is that not everyone can manual block, so they're helpless when that big axe crushes their shield. Learn to manual block, 'spammers' are easy practice since their attacks are always predictable, and two handed weapons are always easier to manual block (except the faster swords), since they're slower and larger (and therefore it's more obvious which attack they're preparing).
Beyond learning manual blocking, there are easy tactics for a 1 handed + shield user versus a two hander. Don't just take their attacks on your shield, try and stay out of their reach and use footwork to avoid their attacks. Since spammers suck at manual blocking, the way to defeat them is to get in their face and hack away. When they're running at you with an attack ready, run backwards for a bit, then suddenly lunge forward and attack them. You'll usually hit them before they can react, and then you can keep hitting them. You can also use buildings to your advantage, since long weapons will get blocked by walls much easier.
). Preferably change attack dir. every now and then just to make them enjoy it more.
