Scorching depends on whether or not the appliance is installed per manufacturer's instructions and if the appliance manufacturer's recommended pot sizes are followed.

I've seen full height splashes that look great. Too often a contrasting splash makes too much going on.

Those are all beautiful quartz. Make sure you do listen to Sophie about the scorching behind the stove. It just has to be installed correctly.

The other thing about these stones, is that they have strong veining. You will have to be VERY CAREFUL when it comes to templating so that they flow well from the countertop to backsplash. Unsightly seams will ruin the entire look. This may require you to purchase additional slabs to achieve this.

I'm usually not a fan of Quartz backsplashes. The thickness of the slabs looks funny up against window and door moldings. Also from the side if the end is exposed.

Extreme grain patterns like in the Cambria Luxury Series colors can look too busy both on the top and on the splash and a quartz splash costs many times what any tile you might select would cost installed.

Brass hardware combined with stainless steel appliances and over the top quartz patterns ups the wall might combine to wear thin on you over time. Think 1990's and all the glass and gold fixtures and furniture. Extremes become dated rapidly.

People with a budget large enough to consider an expensive luxury color quartz backspash will usually be getting professional appliances and as Sophie says scorching from gas cooktops then becomes an issue as well.

To add to what Sophie said: High heat can also cause cracks in quartz and granite slabs over the range. If you put in a range that requires an initial burn, the heat will crack and ruin the backsplash.