A lot of people say things like this and I can't imagine the logic process that leads them there. If the bonuses start earlier, then a character needs a lower score to get the same bonus they'd have had with a higher score in the older editions. In other words, characters can be as effective with lower scores.
no, it is not that everyone else gets bonuses, it is the fact that you now need bonuses to function normally. The ability score was used for situations that hadn't been planned for. you want to jump across that chasm? roll a strength check. attacking, spells, and thief abilities could all be performed based on class, not ability score. if you were a fighter, you attacked better. if you were a wizard or a cleric you could use spells. if you were a thief you could steal stuff and detect traps. the bonuses from ability scores were just that, bonuses. they gave you a bonus to your abilities, but were not the determining factor. a stat that high was rare, so you got a bonus. monster to hit was not determined by any strength bonus but by HD. if i remember correctly, they didn't give you any ability scores for the monsters. they just weren't needed.
since 3.x most actions/abilities have been governed by rules affected by ability scores. i am not claiming 3.x or 4th are bad editions, i am just clarifying that n00bdragon was correct when he said that ability bonuses are leftovers from earlier designs. it works for the design now used. with the whole concept of d20 +[bonus], there needed to be some standard bonuses introduced to the game, such as ability score bonuses. so bonuses started occuring at a score of 12 and the design works, but with just one draw back; you need that bonus to function in the game. there is less game of chance involved and more building up of stats.
i'll get off my soapbox. more to the point, the strength bonus is necessary in the way dnd is played now. a) as i already stated, having strength have no effect on attack would be returning to the old design. personally i think it would be redundant to have a to hit bonus. the strength or dexterity can fill that roll just fine. personally i would like to see some rules where the score was the bonus. b)i think ability scores should be capped. for pcs it should be 18, maybe 19 for one score per race, like how it used to be. but monsters shouldn't get high strength scores just to hit, but because it makes sense. if they are really big like a giant they should have a high strength like a 21, if small like a fairy they should have a low strength like a 1 or 2. c)i think the ability score should affect damage, not just attack. ami going to hit someone because i'm really strong and then not hit very hard? i don't think so. if any thing, strength would be limited to damage, and dexterity to hit. or if you want to limit the bonus that can be applied to that attack, that is pointless as well. why have a higher ability if it is not effective?
there's my rant