Heroic characters have heroic traits. Low reliance on armor signifies natural toughness, which is a desirable physical state. Sexiness and fit/form are also desirable physical states.
Your question and source are more scoped around cultural context. Some cultures-- specifically in America-- it's only really taboo if the female shows skin. If you need an example to prove that, just go to any book store and count the number of super-built-super-sexy men on the covers of the Romance novels. Stores of equal display of topless women here are 'adult only'. Be mindful, that's just America! Think of countries where women are forced to wear clothes head-to-toe. In these, such as the one linked above, it's a no brainer that more needs to be covered.
As long as both genders fit under the same rules in a game, I like it either way. In fact, when I see a powerful character (male or female) messing up hordes of creatures or people wearing bearly anything, I usually think "Damn, he/she is bad ass". On the flip side, I love a good highly ornate heavy armor design as well. In the end, I care more about form rather than function in most fantasy games unless it's a "Super Serious" game with no magic or dragons and stuff.
In the example you linked, however, I like the more covered armor style of the female for sure.
Depends. Generally, I see nude or light-armor as heroic. See: