What? If you write a put option, and it is executed, then you have to buy the stock for its strike price, which will be above its market price (that's why the put was executed in the first place). You end up buying the stock at a premium, not at a discount.

Here's a concrete example. A stock is trading at $100 and you write a put on it struck at $90, earning a premium of (say) $5. Then the stock falls to $80 and the put is executed, so you buy the stock for $90.

You now have something worth $80 and a $5 premium, but you paid $90, so you are $5 out of pocket.

Now you write a covered call on the stock struck at $100, earning a $3 premium (because it's further out of the money the the put you wrote earlier). The stock goes to $110, so you sell it to the call owner for $100. That's nice, you've earned the $3 premium and you sold the stock for $10 more than you bought it for (a total of $13 up). But if you hadn't written the call, you could have sold the stock for $110, and been $20 up instead.

If you also buy a protective put (say for $1) then that's an additional loss you bear in this scenario, since you can't execute the put.

If you're writing options, you're basically betting against market volatility. You'll do alright in the short term, but you'll get absolutely creamed if there's a stock market crash or other crisis.