According to statistics (women) initiate 66% or 2/3rds of the divorces in America. There is speculation that better career opportunities and higher pay have provided women with "more options" than their mothers, grand-mothers, and great-grand-mothers ever had. The more options someone has the less crap they will put up with! LOL!
In all honesty I believe "gender" has very little to do with what someone considers to be their "deal breakers" in relationships. The person who is the most "emotionally invested" in the relationship is likely to bend over backwards to keep it alive. Naturally men who have had their hearts broken are not going to believe that women "work harder" just as women who have had their hearts broken are not going to say men "work harder".
It's anyone's guess what gay and lesbian people would say. As I stated earlier I believe each "individual" makes the call as to whether or not it's worth it to invest more time in a relationship they are unhappy with.