Installing fiber optic cables is not just a "how hard is it?" question. yes, the business considerations do take into consideration the physical issues (how hard it may be [above ground and below ground]), but there is more: Can the company get City\county\state PERMITS to do so? What engineering problems are there? (mountains, existing drainage or other water culverts, etc.?) and then there is also the business consideration of 'how much uptake will be realized if we install the fiber cable?' (how many users in the neighborhood?)
fiber optic technology (to the premises) is here and will not go away (more like CAN NOT go away), however, until the economy picks back up, it may be cheaper for more people to see how much more can be squeezed out of the existing technologies (DSL & cable) before they want to switch to what may cost more for them. SO, in your area, the company may not be able to get the permits, maybe just not yet, who knows? They may also not see customer uptake in your area, yet.
You may not be aware, but Verizon has recently sold-off whole states and partial states-worth of fiber-to-the-premises accounts, in what could have been Business decisions based on profit for stock holders. -If their investments to install it will not be recouperated within the time limit required by their stock holders, it may not be installed for a while.
fiber optic cables are not like traditional copper cables in any way.
If you have a copper cable going from point A to point Z and you want to make a new connection somewhere around M, all you gotta do is cut the wire and solder a branch into it.
With fiber optic cables if you have one from A to Z and you have to make a connection around M, you need WAAAAAY more than cutting it, You need tiny precision mirrors (its way more complicated than this btw) that bounce the signal upward as well as keep it going in the same direction, plus if you mess up even a little bit, you could ruin the cable.
The company is not actually responsible for determining where the cables are going to be laid btw.
Alot of it has to do with the government and the demand. Verizon is not the only one using the cables ( mebbe in some places but definately not most). Other phone companies, Internet Service Providers and of course the gov'ment are also using them.