1) 2♥ apparently shows "8-10 hcp, 2-3 ♠." But what would GIB do on a very bad hand with 3 spades or hands like Ax xx Qxxxx xxxx?
2) Once GIB decided to show a limit raise, it should carry on with that plan. I can understand upgrading to a game bid occasionally, but downgrading and making the same bid with 10 points and 3 spades as you'd do with 6 points and 2 is not a good idea.
3) I know that I can bid 3♠ too but it's not the point of this point.