I have no problem with Rangers having bonuses against Giants (or whatever, but for flavour reasons I far prefer it be Giants).
Here is a good example of unintended consequences. Originally the "giant" bonus represented a whole range of enemies, of all levels, and a healthy proportion of all the published monsters. But as more monsters were introduced, and eventually rangers were allowed to select a group, they became more narrowly defined and represented less of the enemies one might meet.
This post introduced a concept I quite liked: making the bonus be against ANY larger enemy. I think this strikes a nice balance between frequency of usefulness, flexibility for the DM, and respect for tradition.
I also like the relationship it sets up with the fighter. The fighter is a master of warfare, he's a soldier, fighting other soldiers, other humanoids armed and armored like he is. The ranger is the hunter of the giant beasts at the edge of civilization, the things that go bump in the night.
I do have a problem with 2-weapon Rangers who ought to have been Thieves instead; particularly if they are Drow. And did Rangers' fighting abilities get chopped in later editions, because they used to be pretty good in 1e - as good as Fighters, I think.
In 1e they were better than fighters.
In 2e, the change started. Two weapon fighting got introduced, and although they COULD wear any armor, a bunch of abilities stopped working with heavier armor.
3.5 in particular codified their nature as skirmishers more than direct fighters, to match more the way people had been picturing them through 2e. But this also lead to MAD. They had no particular mechanism for dealing damage beyond favored enemy bonuses. So they had to have a high strength to deal any damage, but they also needed high dex to function in light armor. It led to a dilution of the two different concepts, in my opinion. It wasn't that a 3.X ranger couldn't be as good a fighter, but just that it was thematically easy to fall into the trap of a high-dex melee type ranger who had no damage potential.