There are various levels of atrociousness with this stuff so let's start by defining what we mean by masorny:
LEVEL ONE: real bearing masonry. This is what masonry was 100 years ago. The stone or brick actually held up the weight of the roof and the structure above. It had to be thick, more so at the bottom, to bear the weight. The Monadonack Building in Chicago is many feet thick at the base, composed of multiple wythes (a wythe is a single row thickness of brick) of brick. When you seen header bricks they are not half-bricks, but stretchers turned 90 degrees and spanning over two wythes to tie them together. To bear the weight of even a simple roof, brick or stone had to be thicker than 4 inches (the width of a single wythe of brick).
LEVEL TWO: masonry veneer construction. For decades now the mode of construction when masonry is employed is most often as a thin (4" - 6" thick) veneer acting as an exterior finish material and covering the real structural support of the building, be that wood or metal studs or concrete block (commercial block construction is still often bearing - the block you see on the outside of the building is doing the structural work). This mode of masonry is what is most often used in residential construction and the masonry you see, although not holding up the building, is still stacked, stone upon stone, brick upon brick, supported on a concrete foundation. In some unfortunate cases the stone is not real - it is concrete formed units made to look like stone to reduce the cost of the material, but still bearing its own weight.
LEVEL THREE: thin veneer construction. I hesitate to call this masonry because in most instances the whole idea of this technique is to have material so thin, 1 1/2" or so, that it does not need support from stacking the material up but rather is glued onto the wall. Each piece of fake stone or brick is simply glued to the wall often from the top down or in some strange random pattern that does not reflect gravity or any of the rules of traditional masonry. As this stuff is quite thin, as it turns an outside corner either the ridiculous skinny material is exposed or a fake corner has to be produced.
LEVEL FOUR: thin panel veneer construction. This is essentially paneling masquerading as masonry. These are thin panels of stone or brick, pre-assembled, with staggered side edges to hide the panel joints after installation. These panels are very lightweight and inexpensive and if installed with some care as to edges and joints, can, at a distance, fool almost everyone into thinking it is real LEVEL ONE or TWO masonry. Until the panel starts to peel off the wall at least. Usually the material on the panel is not brick or stone but plastic or resin composites.
Now that we have laid out the techniques of deception, expecially in LEVEL THREE and FOUR, let's take a look at the quality of the product. Obviously in all cases if the product being used in made of the same stuff or in the same way as the original it is trying to duplicate there will be a much better chance of replicating its look and application. So, thin veneer brick that is actually cast and molded like brick, from the same clays, will be a much better fake than the vermiculite-pressed products. Same thing with stone - thin cut stone, from an actual quarry, will be far more successful than the dyed-concrete stuff (often known as "cultured stone"). Of course, in LEVEL FOUR, panels of "masonry", none of this typically occurs.
I am all for using masonry, especially LEVEL TWO veneer masonry, in ways that do not try to replicate traditional bearing wall construction. Bricks can be laid up as straight-stacked or panelized, each "revealing" their roles as an exterior finish material, not a structurally bearing material. However, this is rarely done and most often the worst abuses of the fake masonry world occur when traditional masonry is desired but the execution, either in installation or a complete failure of the product, fails to understand what masonry is. What am I talking about here? Well, let's have a little survey of installations that have no idea of what they are doing.
No real mason would ever let so many vertical joints align, especially in a dry-stack type of installation. These fake stone are clearly made in multi-stone units that are simply butted together - usually a sign of concrete faking it as stone. Awful, a product and installation failure.
When the stuff is so thin it is glued on rather than stacked, there is no sense of gravity having any sway in this universe. And clearly the corners of this stuff ought to show that the material is maybe more than 2" thick.
I don't know what to say about this:
In conclusion: I am no fan of any use of LEVEL THREE of FOUR products or applications unless you are going to clearly apply them like wallpaper and have some fun with it. Hey, how about a brick chair? Or a stone door?
For the LEVEL TWO veneer masonry, let's either use it in a traditional way - openings would have lintels or soldier courses, the masonry would never hang in the air - or let's acknowledge its role as merely an exterior protective surface and detail it accordingly.