Why do perfectly nice general descriptive terms so often become tightly bound with one small group and their whole very particular worldview?
Philanthropy? Charity? Those words fit perfectly.
Does anyone sincerely set out to be ineffective in those endeavors? I can't imagine anyone who was knowingly insincere would have trouble also claiming the moniker of effective altruism. Nonetheless, I think the term "effective altruism" is also intended to encompass and imply some additional--if optional--characteristics about the giver or the form of giving, such as leading a more sustainable lifestyle or the consideration given to one's choices in choosing particular acts of charity. But we don't need that term merely for the act of distributing or funding the distribution of mosquito nets--philanthropy and charity are more than sufficient. And, technically speaking, charity has usually sufficed in any event--e.g. clergy who give their entire lives over to charity work weren't in search of more descriptive nomenclature, AFAIK.
Maybe you feel we don't need a word. But I find it odd, and kind of suspicious, when we insist we can't give a distinct name to something that is clearly a thing.
Sure, if you needed a term to categorize. We can build ontologies (and identities) all day if we want. But I ask this: can you quantify the difference between a qualitative vs quantitative emphasis in charity work? Point being: I'm not sure the distinction has much substance or utility. If one's aims are merely to feel good, without any concern for concrete, identifiable impacts, that doesn't fit the definition of altruism or charity or philanthropy. And with mixed motives (as they always are), it's really only the selfless aspect that counts as any of those when we're being pedantic. Even the tax code recognizes this--something is a charitable deduction only to the extent you don't personally derive value from it, and the deduction value is (in principle) the actual value imparted.
But if being able to identify as an "effective altruist" motivates more people to perform more charity, then who am I to argue ;)
I mean, I'll bite the bullet and say yes. People will always choose to have more effectiveness in a ceteris peribus sense, but the best you could say for the actual observed pattern of charitable contributions is that people are being swayed in their giving by all sorts of concerns (social pressures, ignorance, bigotry, etc.) that cause them to trade off effectiveness for those things. And the message of EA is basically "recognize and call out these biases unless they're truly reflective of your values."