It would make sense for Apple to lower its prices to capture and lock in a bigger market share, but only if they were able to meet the resulting demand.
But, if they are constrained by supply chain and manufacturing capacity, then maintaining the highest prices the market will bear makes the most sense.
The author's arguing that's a good short term view and a poor long term one (unless they are constraining the entire SC which does happen for very short periods of time in high tech around chips or screens etc) Those high prices (really margins/profits) will attract competitors.
But, if they are constrained by supply chain and manufacturing capacity, then maintaining the highest prices the market will bear makes the most sense.