Another problem is the chemical bond. As we’ve seen, silicon on earth tends to exist as silicon dioxide. Why? Because the silicon-oxygen bond is strong and stable. In fact, the silicon-oxygen bond takes twice as much energy to break as a silicon-silicon bond. This means that when you have silicon and oxygen together on a planet, you’ll tend to form silicates (silicon-oxygen compounds), not "silorganics." That’s going to significantly decrease the practical abundance of silicon for use by living systems. Now, it is possible to form silicon-oxygen polymers, but again, the bond energy of these polymers is very high, making them much more unreactive and stable than the carbon-carbon bonds in organic molecules. So silicon-oxygen polymers are relatively inert, rendering them much less suitable for use in living systems.

"bonds...too....stable....PAIN!"