I disagree with that. We had a goal keeper, a really good one who would get into most of the other top teams had they already not got excellent keepers themselves. We've replaced him with someone who stands between the sticks and can pass the ball better than his predecessor, but that's pretty much it.
The comparison to the strikers was that we have a low centre of gravity striker who scored plenty, and replacing him with long would give us the same kind of striker but who doesn't do his job that well - score goals.
Another way to look at it is, if another club had got rid of Hart for Bravo and the same performances had happened, would you sit there understanding why he was brought in or would you laugh at that situation?
That's not pretty much it, Bravo is Chile's captain, he was Barca's first choice for the last couple of seasons, he's a very good keeper, with his hands as much as his feet, he hasn't shown the former for us yet, granted.
The reason I chose Higuain is because I was trying to find someone at a similar level but with a different style as we're talking about two different style of keepers.
As to your last paragraph, I'd probably do both, understand why it was done but laugh at the fact that it wasn't working out, just like I did with De Gea in his first season for the rags for example.