Good points on both sides of the debate. Why not do both? Imagine the "we" is really 7.4 billion people (~195 countries) so it would seem that surely we could support each others' efforts to reach both destinations. What an achievement for humanity that would be!
It's a nice sentiment, but if you pool all the money NASA devote to human spaceflight there's barely enough to maintain R&D for a Mars mission with landing in the next 15-20 years, any split in funding between Mars and a manned Moon program, you're seeing a Mars landing easily past 2050.