no, i give you an example:
the rap group public enemy is infamous, they are famous aswell and infamous doesn't mean, they famous for doing bad things, but famous for being controverse, hence the term "infamous". if there is something, people discuss about and have different opinons (also negative ones), you can use the term, that does not, however, make the subject negative in any way.
I really hope that we won't come to the point where we need a separate "urban" dictionary in order for us to understand the writing on this site. Hence, I would recommend sticking to english that actually means what it says.
That's the thing with english, you can use words for a pretty wide variety of meanings, it's not like other languages where it's very regimented. Pretty much every rule in english has dozens of exceptions.
You can't express yourself that well in english, I wish another language would be used worldwide. Being an easy language shouldn't be the prime factor, but an ability to express yourself clearly. Ido (modification of Esperanto) is much better at that.
That's not confined to the english language. In German there's the term "berüchtigt", which is used in both positive and negative ways.
Someone being infamous for his rail aim would make sense, I supposed, because that's a tongue-in-cheek way of expressing a mischievous act inside the game, i.e. to kill efficiently. Outside the game it's just being good at aiming. Innit.
It had great play from both players, the rail shot that made clip quake, and some craze spawn prediction from fat.