I think people trade using market orders because option trading can be a complex system for the new traders.
But I would say market options are not a very good option for beginners because the trade metrics are very different from regular trading. This is the reason people tend to trade in market orders because it is beneficial to determine the specific time where spreads are low rather than to change your whole strategy. I would suggest using demo trading which is provided free of cost from a number of brokers such as Swissquote, fxview, pepperstone, etc. so to understand how to figure out entry/exit points for the trades.