One of the things here is Min/Max here is being misused by many people in this discussion.Min/Max means get the Max benefit with the minimum investment, it's a way of thinking. Whatever rules you set, "nothing below 8 or above 16 after racials" you can still Min/Max. Like if I had a rule like that and wanted to Min/Max, I'd play a druid or summoner cause the Animal/Eidolon will have very comparable stats to everyone, so I really would be twice as strong as anyone else. Normally you'd need buffs and stuff and the Animal/Eidolon still fall behind other PC's, but if you nerf PC's then it's a lot of reward for very little investment.
And if you do Min/Maxing right you also optimize so you don't have glaring weaknesses, especially not more so than those who aren't. So "targeting their weakness" more really means "target everyone's weakness"
Also, limiting the floor a stat can be only lowers the point buy available to them. There's basically no difference between a 7 and a 12 charisma for someone that has a bard playing face. The real effect of a "nothing below 8 after racials" is probably a -1 to AC or Will saves or HP per level as those are the places that the extra points go. There's a reason a guide to a wizard says, "with a 15pt buy get an 18 int, with a 25pt buy get an 18 int." cause all the other stats are just nice to have after setting your main stat to the right place.
I see min maxing as maxing out one thing and living with the minimum in others. Like maxing out offense and not worrying about defense. It works most of the time and when it doesn't no remembers. When it comes to party imbalance as GM I see more with tactics.