I don't know why people set aggressive towards MM
I doubt namecoin is good example to compare with.
As it was told Namecoin was smaller in compare with Bitcoin and the result was not visible
... namecoin was so much smaller than bitcoin this effect was likely negligible.
BitMonero, on the contrary, has already great increases in number of miners.
I support idea of MM as there is a possibility to different way of evolution for both coins just because of their different features.
As far as I know, BitMonero has shorter block time which make this coin make faster transactions and that causes differentiation in finding another block - so the chance of finding new block in both chains is becoming more unpredictable. And no need to mention that mining reward from two coins is better then reward from one coin.
IMHO, the point is if you can get more reward without extra effort when why not to get additional reward?
If I miss the point - could you please tell me what exactly is wrong about MM?