Nekre bhai, the answer to your question is an emphatic 'we are'. the reasons for that are lack of sporting icons, social practices, or what we call 'culture' (not in the sense of arts). I don't believe in racial superiority except in scientifically proven cases, like that of the west african runners. the chinese have put paid to the theory of european superiority in swimming this year.
coming to sporting icons, bengal did have quite a few in the past, especially in football, Gostha Paul etc were extremely famous. India became asiad champions a couple of times just after independence and came 4th in olympics, mostly due to the services of bong footballers. was even invited for the world cup at the time.
the pre independence days also saw the mushrooming of fitness clubs like anushilon samiti (the dhaka branch was particularly influential) which were actually armed anti-british revolutionary outfits. the way they took the fight to the british empire couldn't have happened without sound physique. indeed, one of the leaders of the chittagong revolt was a noted body builder. (as an aside, there is going to be a film on it later this year, directed by a bengali director for a change, who surprisingly enough, used to be a scientist at NASA. I promise it would be far better than the khelein hum.. idiocy done by abhishek bachchan. try and watch it
)
there were also a couple of bengali Mr Universes, a different category of the same competition brought arnold scwarzennegar to the limelight.
yet, whatever sporting icons we had unfortunately couldn't jump start a culture of sports because of the pervasive poverty and unemployment. in the first few decades of independence. people wanted a safe option, studying and getting a job was always the safer and surer option. conversely, in some countries, like say ethiopia, kenya or jamaica, sports is a way of getting out of poverty and thus that social dynamics has created a sporting culture.
in a nutshell, to create a sporting culture you need sporting icons to jumpstart them and it has to be reasonably safe to take it up. this is basically the american/free country/relatively prosperous country model. the govt may or may not play a part in making sports as an occupation safe. (UK for example does, US largely doesn't)
the other ways are
a) chinese/north korea way : create a country wide net with pyramidal structure selecting candidates towards better and better standards. force those who have natural aptitude to train at a fierce level whether they like it or not. ruthlessly weed out at every stage those who do not make the mark, without bothering what they do for the rest of their life (many chinese national and olympic players who do not succeed end up as sweepers and janitors)
b) kenya/jamaica way. sports is comparatively one of the best avenues out of poverty, huge talent pool, support structure exists, talent and training takes care of rest.