What gave you the impression they want to be objective? The Economist is very upfront about their bias and positions, more so than any major newspaper I can think of. It's pretty common to see "this newspaper supports x" in an article about a controversial issue. It shouldn't be your only news source, but they've never pretended to be dedicated to objectivity like Reuters or something.
As the GP said, especially if you know the topic well, Economist fails to impress you with the sometimes "shaky" facts they embed to make a point. What I don't like at Economist the most is the divine-like inner voice they are using to report on a totally controversial area in a totally foreign topic and choose a side as if it's very easy to choose sides. For example, you're a banker reader in London, and they give you bundled, consumption-ready opinion about why Mr X in LaLaLand is a better match for governing the fiscal politics and not Ms Y.
It's as if they are ruling the world rather than doing journalism.
My point is that I am intentionally paying for bundled, consumption-ready opinions about the world. I have other news sources for more detailed "just the facts" coverage of places and subjects I care about, but nobody has enough time to keep up with the entire world at that level. The Economist gives me a nice overview of world events from a well-defined, consistent, relatively moderate viewpoint, and often covers topics that other "general interest" news sources don't.
I completely understand that not everyone agrees with their views or likes this style of journalism, I just disagree that there's any "trick" or false advertising going on.
I want to know why the villains (people, corporations, governments) they attack justify their actions. Give me a soup of conflicting ideas to ponder instead of cherry picked truths.
If an author makes up my mind for me, I lose interest.
I would be a hypocrite if I didn't mention some good points about the magazine. The writing style is superb and this may sound strange but I find that my inner voice resonates with what I am reading. There are many writers yet the magazine as a whole is very coherent and humor is used expertly to liven up some dry topics.
So there you have it. Read it but don't forget that you're drinking their Kool-Aid.