A couple of rounds is often the difference between success and death in D&D 3.5. Just sayin'.
Sure, and if you couldn't fetch spells in advance that would be a problem.
The thing is, we're not arguing about fetching spells now vs. having them prepared in advance, because sha'ir and wizards are equally able to have whatever spells they think they'll need prepared. You are saying that the reason sha'ir is T2 instead of T1 is because they get fast-prep instead of Scribe Scroll as a bonus feat.
Seriously. Read back over what you said.
That's not what I said. I said that, with Scribe Scroll, a Wizard has a spell that he doesn't typically prepare available to him as a move action (thanks to Handy Haversack et al) or full-round action by default, versus a Sha'ir having that same spell available to him in 1dHandful
rounds. Which scenario is likely to be more useful?
For Clerics and Druids, the useful spells not typically prepared are
most often Cures (for Clerics) and Summons (for Druids), in my experience and in reading various PbP forums. Hey, look! They can automatically sub out their prepared spells for those respective choices, by default. The Sha'ir? Not so much. They can get them, sure. The time it takes could well make that Cure spell less apropos than a Raise Dead, though....
See also: TML's commentary about spellbooks relative to gens.