God yes it favors min maxing! We've gone from having 1 dump stat (usually CHA) to 3. Since stats are determined from the better of 2 and attack rolls are always from your classes 1, much easier to have 3 8s and not care (or 10, 10, 8, whatever). The 3 dump stats vary from class to class but they are there.
Yes, that 12 dex might still provide you a +1 initiative bonus despite being otherwise useless in heavy armor, but that doesn't count, nor does a secondary ability that you can completely ignore by choosing powers that don't use it.
The exceptions are there, but they are small and usually not worth sacrificing any of your 3 (or 2) primary stats for.
In 3ed, having a bunch of 14s was decent in a number of builds. So you have 2 less to hit than someone with an 18, big deal? You have your fighter base attack and +1 to hit with weapon focus, +1 with point blank shot, +5 from magic weapon, etc....
In 4ed Its all about getting extra points in your Attack roll stat, since Defenses and Attack rolls scale evenly. Your primary ability is one of the only ways to do that in 4th ed.
Now, in 4th ed, OMG how useless balanced ability scores are. Can you imagine having 14, 14, 14, 14, 12, 8 as starting stats? You really should start with at least an 18 after racial mods in your primary stat or you are a bit gimped IMO.