This sort of ticketing thing is a trivially solvable problem. It is solved at every airport in the entire world millions of times per day. You provide the name of each concertgoer when you buy a ticket, and they show up with their ticket and ID. You often need to show your ID at these kinds of venues to prove you're old enough to drink beer anyway.
I agree, mostly. What do you do for people without an ID (and without a parent)? Think of the number of people at a Taylor Swift concert who are under 18 -- a lot. Also, checking the name between ticket and ID will slow down entrance by 2-5 times, I guess.
Said festival does their own ticket re-sale to avoid scalping but mainly to avoid shady sites that are known to allow the selling of counterfeits. You can only cede your ticket, not sell it. It is not perfect (e.g. if you don't find a buyer for the same price, you can't sell it at a lost to recoup some money. You get your ticket back) but at least is not as bad as the one from Ticketmaster.