The article lines out how to neutralize an attacker mindlessly building a chain of useless transaction but this obviously does not solve the problem. What if the attacker forks and rebuilds the chain of the last week but randomly leaves out every tenth transaction while slowly poisoning the genuine chain with useless transactions until the algorithm decides to switch? You just undid thousands of transaction originally confirmed a week ago. If you could just make up a couple of rules to prevent all 51 % attacks they would not be an issue in the first place. But this again would imply that it does not matter how the computing power is distribute between the good guys and the bad guys which obviously completely contradicts the fundamental design of Bitcoin.
EDIT: Deleted parent comment quoted the attackers-can't-list from [1].
You are quoting the wrong part. This only holds if the attacker does not try to build a side-chain.
It's much more difficult to change historical blocks, and it becomes exponentially more difficult the further back you go. As above, changing historical blocks only allows you to exclude and change the ordering of transactions. It's impossible to change blocks created before the last checkpoint.
