Is it then better to have a net credit in a spread bullish call strategy

In a bullish call spread strategy, the goal is to profit from a moderate increase in the price of the underlying asset. The strategy involves buying a call option at a lower strike price and selling a call option at a higher strike price, both with the same expiration date. The net premium paid to establish the spread is typically greater than zero due to the difference in strike prices and premiums.

Having a net credit in a bullish call spread strategy is not the typical outcome. In fact, it is the opposite of what is generally intended. A net credit in this context would imply that the trader received more premium than they paid, which is not the case in a standard bullish call spread construction. The net premium paid is the cost of the strategy, and it is this cost that determines the maximum profit and loss potential of the strategy.

The key point to understand is that the net premium paid (or net debit) is the price you pay to establish the position, and it is this that influences the risk and potential return of the strategy. A net credit would imply that the strategy is being funded by the premium received from the short call option, which is not the typical way a bullish call spread is executed or managed.

In summary, the goal in a bullish call spread is to have a net premium paid, not a net credit. The net premium paid is the cost of the strategy, and it is this cost that should be considered when evaluating the potential profitability of the strategy.