There are a lot of discussions on why Apple changed the new MagSafe power adapter. First of all they made the new one thinner and therefore incompatible with the "old" MagSafe. The reason for this, Apple told us, was that the new models become thinner and thinner and at one point the MagSafe adapter would be to thick for the new MacBook body. This is kind of sad because until know you could charge every mobile Intel Mac with the same adapter. But at some point you have to change even the most popular connector (we will most likely see the iPhones/iPods/iPads Dock Connector change) So even if we are not yet at the point where it really had to change, I am ok with that.
The other thing that changed is the form of the connector from an L form to the T form which it had at the beginning if it‘s life. There are a lot of complaints about this too. Most of them saying that the the L form is much better. I think this isn‘t that easy to say. Since pictures can say more than words and I am not that good at writing words I made a video:
The purpose is to state two points. First of all, not all MagSafe 2 magnets are too weak. Mine is more on the too strong side. Second, even if the L shaped connector has a much weaker magnet, if pulled from the wrong direction it is extremely hard to pull of.
Correction: I wrote MacSafe but the connector is acually called MagSafe.