The +1 to all stats advantage is not as huge as it seems. It tends to mean you're a little better at stats you don't use all that much. IT actually won't mean that all your low stats are suddenly good and you're getting an extra +1 in many stats compared to a character made from another race, suitable for the class.
Take an example archer ranger. A Human with +1 to all stats could have S12, D16, C14, I10, W16, Ch9. A wood elf could have S10, D16, C14, I10, W16, Ch8. So the only difference is that the human has a marginally better strength (or whatever). But it's one stat, which isn't hugely important to the class, being improved by a +1 modifier. That isn't irrelevant, but it compares against the wood elf's ability to hide, move faster, see in the dark, better saves and free perception skill.
S12, D16, C14, I10, W16, Ch9
S10, D16, C14, I10, W16, Ch8
This is mostly true for a player that wants two 16s to start with (one of them Dex) or who wants a 16 Dex:
S11, D16, C14, I10, W14, Ch14 Human
S10, D16, C14, I10, W14, Ch12 Wood Elf
Alternatively if a player only wants a single 16 that is not Dex:
S9, D14, C14, I16, W14, Ch12 Human
S9, D14, C14, I16, W10, Ch12 Wood Elf
This PC has +2 in one stat (or +1 in two stats).
Or he could go:
S9, D14, C16, I16, W10, Ch12 Human
S9, D14, C14, I16, W10, Ch12 Wood Elf
For a Wizard, 16 Con (undead saves and concentration checks and hit points) might not seem a lot, but it adds up.
The wood elf cannot be a 16 Con 16 Int Wizard at first level. Not possible.
In fact, a human could have 3 16s (and 3 9s) if he so desires. No other race can do that.
So yes, for a player who does not mind being shoe horned into one of a few specific non-human races, just so that his class shines a little, those non-human races are good.
But then again, any PC can be human and shine just fine. +2 over a non-human in a single stat modifier is not worthless for many class combos.