As usual for my knitting notebook, this technique and an interesting discussion about it, started with my husband.
It all began when I planned an entrelac sweater for that man. I decided to knit each block in a blue yarn with every block being different from any of its neighbors. (Cannot believe I was undaunted by the prospect of sewing in all those ends!) Not knowing how the project was going to evolve, I dispensed with the usual 'triangle row' and started by knitting rectangles, attaching them as I went.
Unfortunately, he saw the knitting and decided that it was 'too busy' for a man's sweater. So, I put it down for awhile (a couple years, actually) while trying to decide whether to use the blue yarns in a very different sweater for him or to carry on and make the sweater for me (- the better idea!)
Eventually, I picked up the Entrelac at a Different Angle idea again, deciding to try it without all the color changes (and resulting loose ends) in a vest for myself.
While watching me work on the vest, he became curious as to just what was out of the ordinary about it. After explaining the 'usual' triangle rows, etc., he asked the million dollar question: Why do it the old way when this way seems much easier?
I believe that the answer can be found in old knitting. In my knitting library, the oldest examples of entrelac show up in stockings. (True, my knitting library isn't definitive. If you have better information, please enlighten me!) One example is the stocking from Gotland included in Swedish Sweaters, New Designs from Historical Examples by Britt-Marie Christoffersson. (For information on this reference, link to More.)
If you pick up and stretch a piece of entrelac, you will find that the stretch is best for stockings in the traditional technique (using a foundation row of triangles.) It gives the most comfortable fit. Traditional entrelac is also the easier way to work shaping in rounds of variously sized blocks.
When modern knitters use entrelac, we aren't always taking advantage of the stretch and shaping. A stunning exception to this is a sweater by Gwen Fox, illustrating "Knitting a Basketweave Look-Alike," in Threads magazine, (For information on this reference, link to More.)
The mitten, at left, was knitted by my good friend, Judy, and perfectly illustrates the use of differently shaped blocks to decrease circumference. (The pattern is available from the Three Kittens Yarn store in St. Paul, MN.)
If not using the 'finger puzzle' property of entrelac, or using rows of differently sized blocks, there is no reason to knit it at the usual angle.