No one is attacking your right to give moeny any way you choose, so you have nothing to defend.
But you seem to be attacking people who want to use something gimmicky as a way to fundraise.
I don't see why you would do that. If I spend £30 on stuff to create the gimmick, and treat that as my donation as I have no plans to claim the money back from my charity, and that gimmick goes on to raise hundereds or pounds, how can you possibly argue that it's not a good thing? 
I agree with you about Children in Need tbh, although I think Comic Relief is worse. They do donate a huge amount of money to good causes, so I don't feel I can criticise too much, but it does annoy me that people (especially celebrities) only give money because of teh gimmickyness that surrounds Red Nose day and Pudsey Bear.
If all the people that bought a red nose, or a spotty handkerchief, or sat in a bath of baked beans for sponsorship, would just give that money directly to charity in the first place then the charity would get more of the money and they would be no need for the stupididty. But they won't. There are lots of people who only ever give to charity when they get something in return, or when they can be seen to be supporting a charity. It's sad that that's the way it is, but that is still the way it is!
The money that comes from those people is as good as anyone elses money so if gimmicky works then gimmicky is the way it has to be. Because those that don't need the gimmicks to give will already be doing it, and even then charities will still be struggling.