Compare three bubble situations...

In Hand 3, you're SB and it's folded to you. That means only one guy left to act. In Hand 1, you have two people left to act (SB and BB). So in Hand 3, its less likely BB has anything decent, and regardless, he'll only call your push with top 15% or maybe even less. In Hand 1, two people left to act, there's a chance one of them may have AX or KX, and assuming their calling range is the same, its more likely one of them will actually call you.

For Hand 2, you're big stack, so you just want to minraise or 3X raise (minraise is usually fine because a minraise at this lvl is almost equivalent to 3X raise) to steal, or to get some action.