Dude, Cornish's views on stuff, and the technology he works with, are fairly dated.
But there is kinda a point to hating on true bypass... sort of. Even cable with relatively low capacitance (ie, fancy schamncy stuff) will result in a slight loss of highs on cables that are over 10 feet. That's easy enough to get around - just turn the treble up a bit on your amp. Or in Jimi Hendrix case, use a shit load of cable with relatively high capacitance per foot to roll off the ear bleeding highs in his amp/fuzz. So you run one true bypass pedal, a 10 foot guitar cable to your pedal, and another ten footer to your amp, you're going to be losing a substantial amount of highs. Which is fine, but somewhere you get to the point where you either can't, or don't want to keep compensating for the loss of highs. Or it may be that you want a more consistent sound, one that is not dependent on using particular cables with a particular length.
Enter the buffer.
A buffer is a small circuit that has high input impedance, low output impedance, and linear gain. Impedance is kind of analogous to resistance, except of AC signals (like the one coming out of your guitar). It should ideally have a flat eq response. The point of all this, is that a circuit of this type is a really good way to preserve your signal as close as possible to what is coming out of your guitar. Or the previous effect. Whatever. Buffers are kind of like parenthesis, and they ensure that whatever is between the parentheses behaves the same and is unaffected by stuff outside of them.
Generally, most signal chains will be better off by having at least 1 buffer in there somewhere - either at the input of your chain of pedals or the output, or both. Until relatively recently, it was problematic to create pedals that had both an LED indicator, a stomp switch, and true bypass. The sort of switches that most ILF builders use (3PDT) didn't exist. So a simple mechanical bypass was not possible. The solution was to simply design a bypass system that involves some sort of buffering.
There is nothing wrong with buffered bypass, but it got a bit of a bad rep as quite a few of the earlier buffered bypasses didn't have particularly linear buffers - that is, they had a substantial effect on the signal, and that effect was often felt to be negative. For example, I've got an old Guyatone delay I dig, but the buffer increases the treble content disproportionately. You put a lot of pedals with dodgy buffers in a row and you're doing all sorts of crap to your signal.
Most buffers these days in Boss pedals etc are really good, and I'd guess most people who hate on buffers are simply hearing the treble roll off in their cables being negated by the buffer. Cornish's beef with TB is the signal rolloff you get with larger cable runs, and the perhaps inconsistent behaviour you get with a large TB rig. I think he's got a valid point. On the other hand, I prefer to buy TB pedals so that I can choose for myself what buffer I want, and where I want it.
A great buffer, that is easy to build, can be found at
http://generalguitargadgets.com/project ... -ic-buffer