I trade both directional and market neutral. When you trade market neutral, it doesn't mean that you don't have a view, it means that you have a view on the market trading sideways or a view on volatility. So if options allow you to express that view, why would you want to stay out!? Deep ITM options can be used as a stock substitute, but options expire, stocks don't. Also, deep ITM options are very illiquid and have wide bid-ask spreads. So it's not really a bowl of cherries, if you ask me, but like every strategy, they do have their place and time. The key is figuring out which strategy to use and when.
A limit order doesn't guarantee an execution. If you need to get in/out then you are forced to pay a lot in slippage.
An advantage of deep ITM options is less risk in the event of an underlying collapse. But you're still going to get clobbered by the initial drop since the delta is 1. Another adv. is leverage (2 deep ITMs is roughly equivalent to margining the stock). Disadvantage is aforementioned wide spread and illiquidity. Either way, you still have to get the direction right.
In essence, the higher the delta, the less liquid the option contract? If this is the case, why is that?...wouldn't traders want an option that follows the underlying as close as possible? Why buy an option that has a delta of only .10?..whats the point in just making 10% of the stocks price movement?
Leverage. The deeper ITM you go the less leverage and vice versa. And, no, traders don't necessarily want an option that follows the underlying as close as possible.
That's what makes a horse race. Some like good chance of a more modest payout. Others like the long shots.