An atheist dilemma

Militant atheists are duplicitous on what makes life worth living. On the one hand they say you don't need God to have a meaningful life. What makes life meaningful is what's meaningful to you. What you personally value. 

On the other hand, they attack Christianity for giving believers false hope. Christians waste the only life they have by banking on the deferred reward of a nonexistent afterlife. They fail to make the most of the only life they will ever have in the here and now through time-consuming religious devotions and prayers and anxieties over sin and sexual inhibitions, because they're staking their ultimate fulfillment on a future payback that will never happen. There is no hereafter, so it's now or never. 

Notice, though, that their objection is diametrically opposed to how many atheists justify the significance of their own existence. Many atheists say subjective meaning is sufficient to make life worthwhile. But then, why can't Christians have meaningful lives as Christians, even if (from a secular standpoint) Christianity is false? Sure, it's subjective meaning. It doesn't correspond to objective reality (from a secular standpoint). Yet the same atheists insist that your sense of purpose in life needn't correspond to objective value. Rather, value is what is valuable to each individual. 

So why do militant atheists make their mission in life talking Christians out of their faith, or dissuading people from ever considering Christianity in the first place? Is it because they think Christianity is based on wishful thinking? But what if wishful thinking is what makes you feel that you and your loved ones are important in the grand scheme of things? An atheist can't object on grounds that that's a sentimental projection, for he that's how he defends his own position. 

So the atheist has a dilemma on his hands. If subjective meaning is good enough for atheists, why isn't that good enough for deluded Christians?