Every single person reacts to the game in a different way and even quite similar in tastes gamers can like or dislike your game design. On the GameCrafts conference in Kiev was an interesting speech about human's personality influence on the preferences and derision in games.

What is is your opinion about it and does it really meter on the prototype stage of the game design?

For prototyping, that seems exactly right time to explore it.

Prototyping is a time to experiment with ideas and do things wrong, or do things somewhat well, so you can identify what works, what doesn't, and what works somewhat but needs improvement.

I think in the talk they're in the right direction of discussing how many different play styles can affect things for some games. If it fits the game genre, and if you have development time/budget, then go for it. People are different, and if it makes sense in your game to adapt for that, then do it. Otherwise, don't.

When prototyping, you begin to build a foundation for your game.  When building a foundation, it's important to have a single focused vision on what your game should be.  frob is right, you should be experimental to see what works, but at the end of the day, you should know who you're making your game for, and the archetypes mentioned in this talk is an excellent start.