I am annoyed, annoyed at the free pass given to stupidity and lack of responsibility. Also, you may think it reasonable to think so, but clearly given the current evidence you’d be wrong. If you choose to carry on with your “reasonable” view, well, that’s your choice.
You've mentioned responsibility twice. For what?
Assuming you are going to say responsibility for reading the small print of where your money goes. OK. But we do have some laws in this country (and in the EU) for making false representation.
A "national" charity is reasonably expected to spend it's money in its home country. It's right there in the name.
Other international charities often have words such as "worldwide" or "international" or they simply make it well known in
all their media and campaigns that they operate internationally. As mentioned previously there is unlikely to be any issue with something like Cancer Research UK funding international research because it's still research, and still of benefit to the UK (indeed it benefits everyone simultaneously because information is not a finite resource).
In this case UK operational funding was short by 6.3 million, and at the same time foreign aid projects totalled 3.3 million, over 50% of the shortfall.
Now lastly something we haven't touched on yet. Fund-raising requires time, effort, and resourcing. There is potentially an opportunity cost in directing efforts towards fundraising for international operations. Staff and other resources dedicated to international fundraising can't be working on UK fundraising efforts. Perhaps that's a drop in the ocean but it's either an extra cost or its a resource utilised away from the core mission.