firewall's [are they essential?]

i was at a clients home this morning and after fixing her nic problem i found that the xp firewall was turned off. when i asked the client she told me that the outfit she was doing business with stated that a firewall was NOT needed at all. one of my other clients was told that a computer friend told her that a firewall was not needed as long as you do a xp broadband connection.

i do know that most of the high speed devices from isp are now intelligent routers with a built in hardware firewall and hdw firewalls are better for the most part than sft firewalls. i realize this. i also know that there are still a ton of dumb devices that are high speed capable that do not have built in firewalls. i also know that for the most part if one is a dial-up that a firewall is not as critical as if you are high speed because you are not normally on the same amount of continual time as with high speed.

what am i missing here ??? why would these outfits tell their customers that firewalls are not needed - period. this goes against everything i have learned in years and honestly i have never heard anyone ever says this before.

am i wrong or are these others wrong ???