Computer science is coming full circle on performance. For decades, people worried intensely about performance and squeezed every ounce of speed they could from their code. But today the story is changing. The growing popularity of functional programming in the mainstream is encouraging people to think at a higher-level of abstraction. These people are often found reciting Knuth's famous quote "premature optimization is the root of all evil". Unfortunately the extremists among them are taking this too far and architecting systems with no regard for performance. The only fix is then tantamount to completely redesigning and reimplementing the entire system.
We can only conclude that this extremist form of "premature optimization is the root of all evil" must be considered harmful. Joe Duffy of Microsoft already expressed a similar opinion.