I don't spam off grenades as soon as I see someone. If I think a grenade or even multiple grenades will benefit me in a battle situation then why would I not try to give myself the edge over my opponent and ultimately come out on top, helping my team to victory? Yes, spamming of grenades can be annoying, but isn't it annoying when you are shotgun-meleed or sword blocked? If it helps you then I don't see the problem. As for the matter of people throwing grenades at you, then you have to get our of their way. Hang back and throw grenades, like them, or stay back and pick off headshots because the grenades have taken down the opponents shields.