Others have found this a surprising claim, so do I. How has it been weakened or erased? Are they talking about different mental elements or creating offences which do not have a mental element at all? The first doesn't strike me as particularly novel, or objectionable.
> This is a slope that we have been sliding down for some time. While ignorance of the law has generally been excluded as a defense in criminal cases, our system of laws is becoming so convoluted that it is almost impossible to know and understand the applicable law.
This isn't a good thing by any means, but the issue of the law being unknown or incomprehensible to laypeople is nothing new. Take common-law requirements. Honestly, how many people read the relevant case law, or even understand its general effect? People have bumped along for, literally, centuries knowing little more than the broad outline of the law.
I'd also point out that "increasingly codified" isn't synonymous with "increasingly convoluted"; common-law rules are often pretty convoluted.
> Thus we are all at risk.
I'd actually suggest that the general level of legal knowledge has improved. Thanks to the Internet it's at least possible to get at the content of laws without access to a specialised library.