From what I understand about Germany (the only country I have first hand experience with) the cable companies were not multi bilion dollar powerhouses at the time the Internet became more widely available.
Cable TV in the states dates to the 60s, whereas when I was last in Germany, there was little cable.
When my German relatives came to the States in 2002, they were shocked that we had the Internet IN OUR HOUSE. So the answer to your question (at leat pertaining to Germany) is
(1) The cable companies did not have the resources to snap up ISPs
AND
(2) The Internet was not as widely available to individuals as fast as it was in the states, so it was not perceived as the same kind of competitive threat.
WODIN,
There are no such things as "laws that favor competition". Only the absence of regulation favors competition. More laws always equals less competition.