Are clone games profitable?

Four and a half years ago, the Fight Club appeared on the Internet , an online game that gained incredible popularity and brought huge profits to its developers.

Since then, the clones of BC began to breed in large numbers:
Arena ,
Territory ,
Carnage ,
Free land , etc.

All these are games from the series "We also made BC". The principal differences are zero, the unprincipled ones are not worth talking about.

Of all this post-BC series, perhaps only TimeZiro can be distinguished .

I do not understand. Why reinvent the wheel and hope to make money on it?
Quake is different from Halflife, and Halflife is different from CounterStrike ...

Why are Russian developers of online games so obsessed with cloning BC?
A fresh idea and a bit of imagination will it not pay off much faster than an old and boring BC with new and not always the best pictures?