Nonsense. Lets say you're creating a Star Pact Dwarf Warlock. You get +2 from your race. You could set your stats so that you have an 18 Con, your Int is your next best stat, and you have a smattering of other things. You could then select Constitution based attacks for your Warlock. That would be one option.
Another option would be to set your charisma to 16, your con to 14 (16 after racial stat modifiers), and put the remaining points into Int and the other stats.
The first option gets you +4 attack and damage with all of your abilities.
The second option gets you +3 attack and damage with all of your abilities. But look at the choices you gained. Your constitution based attacks generally target Fortitude. Your charisma based attacks generally target Will. And of course both characters can use Eldritch Blast versus Reflex.
Not only have you gained the option of selecting a wider variety of powers, you've gained the option of attacking multiple defenses. This is NOT a trivial benefit, it only really cost you +1 attack and damage.
The same is true of clerics (strength for AC, wisdom for Reflex and Will) and Paladins (strength and charisma based attacks have different generalities about them). I can't think of anyone else with this issue.
I'm not going to claim that generalizing is objectively better than specializing, but its certainly not a foolish decision. If you're decent at eyeballing what defenses to target, that +1 attack and damage you spent could grant you significant increases in your chance to hit.