I feel like this is a very important point that is getting lost.
Of course costs are going to be higher and profits lower (or even negative!) when you're laying lots of new fiber and deploying new equipment. Maintaining that equipment in subsequent years will cost much less and you'll make more money those years selling service on it. There's nothing inherently wrong here.
Yes, costs naturally will be lower after the initial large capital expenditure.
No, this so called modern cabling has not resulted in cheaper and faster access fees. Americans pay some of the highest fees for comparable speeds. 
Lastly, the flip side of the coin is that if the ISPs figure out they can still make $$$ from not having to invest in upgrading infrastructure, then there is very incentive to do so.
All the last mile ISPs were doing circa 2000 was hooking smarter silicon on their existing copper.
The first big last mile fiber builds started towards 2005 I think. (fios etc)
It would be interesting to have a line on that graph showing when ISP's weren't required to abide by FCC rules because they were not classified under title 2.