I played a bit of rugby in my school days but I find NFL a tad cooler

These are both physical games but very similar but surely rugby is alot more hardcore than the NFL? (No protection)

England seem to have football as their main sport (rugby 2nd?) and the americans seem to worship the NFL (basketball 2nd?)

Apart from maybe not understanding it what makes NFL so attractive to the americans and rugby so loved by the english and could each country (or why) did they never adopt each others sport.?

Imp