That blog post is one person's opinion.

rjbs makes a fair point about Sub::Uplevel being a risky thing to have about unless you are sure you really need it. (A bit like having an bottle of deadly poison in your food cupboard), and by extension it is not a good idea to have it used in standard testing code that uses Test::Exception, that otherwise has no need for it.

However, he then uses that as an excuse to write a totally new and non standard exception testing module with an incompatible and less expressive API. I think that rjbs would have better spent his time creating a patch for Test::Exception that made Sub::Uplevel optional, so that the danger could be removed without creating yet another perl module that mostly replicates existing functionality.