Bit rot is a feature. It allows genes that don't impact survival to attain greater diversity within the population so that, if the environment changes and the gene becomes relevant, some part of the population may be better able to adapt.
This is just hubris.
A worm has the same number of protein coding genes as us. Obviously the 'non-functinal' DNA is doing something important, we just haven't worked it out yet.
I would be very hesitant to criticize an evolutionary construct that has developed on a billion year timescale.
Back in bio class, my professor said that in lab tests, replacing the non-protein-coding dna with something man-made hasn't been shown to have any effect. (Removing it does have an effect).
Larry Moran has a lot of good material on this http://sandwalk.blogspot.com/2008/02/theme-genomes-junk-dna....