Raising blocksize causes another problem that is near 52gb blockchain data. Downloanding the whole chunk of blockchain takes a lot time and and hard disk space. No many ppl are patient and persistent enough to use the bitcoin qt.
i know thousands of people that download movies, download games.. EG GTA5 is 75gb and loads of people dont see that as a problem, and as for expansion, in the future there is a thing called fibre optics... oh wait its already here, so i guess that solves that problem.
then we come to the point that in the gold industry:
not everyone owns a plot of goldrich land
not everyone owns a gold smelting plant
not everyone owns a gold shop
not everyone is a huge gold investor on the markets
but im pretty sure everyone has something in their house that contains gold.. and thats all that matters.
not everyone needs to get fully set up with bitcoin. just the ones with large amounts invested.. for instance if you have under 1btc, i see no point going full bitcoin-core..
But then there are those who see the need and do provide the full nodes, it will all even out. Most day to day users of bitcoin do not want to use a full node, updating and having a 52gb chunk of data on their device, but having a dedicated machine, to support the blockchain is not that weird, or maybe it is, but most of the early adopters are a bit weird and nerdy 
i agree the whole "it will take up too much space..." is such a crap excuse. especially with 2 terrabyte harddrives being cheap these days, more than enough for 2 years storage and then cloning the drive onto the next level of cheap drives in 2018 (many terrabytes) wont be a problem.
its the kinda weak excuse of 2000 when it was said that online gaming wont take off because most users are on dialup.. the next year ADSL came about