There were plenty of dangerous stadiums apart from Heysel and had been for most of the previous hundred years. The loss of life at Ibrox (1902 and 1971), Burnden Park (1946), and subsequently Valley Parade (1985) and Hillsborough (1989) testify to that. None of the incidents could be directly related to hooliganism apart from Heysel.
Liverpool managed to create a media image of their fans as 'good natured scallies' that resulted in much of the blame being attributed to the state of the stadium. The fact that the stadium was falling apart and that there wasn't better segregation, is no excuse for Liverpool fans charging at police lines, breaking through and attacking the Juventus fans. In the stampede to escape, part of the perimeter wall collapsed. This allowed most to escape but 39 were crushed to death before the collapse.
I suppose that Liverpool could argue that it would not have happened if the supporters were separated by barbed wire and trenches (plus a few landmines) but it doesn't really wash.