cayenne - You have a nice service deal there. Kudos! Unfortunately most folks don't have a deal like that and pretty much all residential ISP services block incoming web requests to prevent web hosting, email hosting, ftp hosting, etc. So while you have the ability and the bandwidth, most don't.
The other problem is that if everyone was fortunate enough to have what you have, they still don't have the time, skill or desire to build and maintain a web site. It's a lot harder than people might think. And for those that have the skill and the knowledge, they have the distinct pleasure of dealing with all the security and breach attempts that constantly occur on the Internet.
Paying a reputable place like Zenfolio, GoDaddy, etc to do the heavy lifting is usually a much better choice and the up time is better too.
Building a website is a great experience and very rewarding but you have to enjoy it for it to be worth the effort and time.