Disagree. I'd say they are split fairly evenly.
eh. how many powerful women have been killed off? Catlyn Stark and Lady Tyrell? the women in the show have done the most growing, and have been, or have become in some cases, the most cunning characters in the show.
Ned, Robb...both dead because they didn't pay attention to the big picture...Ned too idealistic to last, Robb, well, he was thinking w/his you know what....(can't blame him really lol)....Littlefinger...dead, underestimated the stark girls......Kahl Drago, dead, Dany's brother, dead because he was an ego maniac that had no clue (one of the best death scenes in the entire show)....all the baratheon men, dead and all for being stupid.......Taiwen Lannister, dead....took Tyrian's whore and underestimated both his sons, and daughter......even the last two male kings of the 7 kingdoms were children being led by cerci or they tyrell queen wannabe, and both wound up dead....one was a psycho path a lot of people wanted dead, the other was to weak minded to be an effective leader, as evidenced by his cowardly suicide.....
the only two men that have any power, and have been there they whole time are Jon Snow and Tyrian. and both had to rise up from meager beginnings....real struggle as characters. both had a lot to overcome and both have natural leadership ability. but that's really it. maybe you make a case for Euron Greyjoy, but as of now, he's just a servant to Cerci. Jamie...he's no real power either....Cerci's lachey, and now a man w/out a house....
again, i don't have any issue with it all, i think it's enhanced the show more than not....but it is what it is....and i'm still not saying that's a mary sue intent or anything.