You don't have to be a carpenter to know if a house is built poorly, just if you try to describe the cause. They were right in their criticism of transaction fees, but were off in what was causing it.
Block size is limited by bytes allowed in the block, usually about 7 transactions a second (on average) for Bitcoin. Increased demand for transactions increased tx fees.
The length of the chain can affect processing power and bandwidth, as each block contains all previous blocks.