Expected by who? If the employer wants to offer the option that's fine, but there should really no expectation or 'pressure' from either the employer or other employees for an individual to do so.
The real irony is that you're criticising the people doing the ice bucket challenge for doing it just for attention, yet you won't stop telling us about how you donate regularly and that you think everyone else should be expected to.
In reality both the ice bucket challenge and Captain Planet is putting an expectation on someone to donate, only the ice bucket challenge does it via nomination/peer pressure. Either way it isn't really voluntary giving thus IMO a wrong way about it.
Also currently it is World Water Week so the waste of water during this time, however small it is inappropriate IMO.
I accept it has been a hugely successful campaign though so is great for those people that don't give normally.