The two are connected. The more niche (or custom) software is the more resistant it is to porting. There's going to be a lot of Wintel based stuff which is a quick and dirty port from Windows with few Mac native elements. The years where Mac was Intel compatible made the platform more attractive to people who worked in a mostly Wintel environment. There is almost no incentive for those who ported software to the Mac because it was easy to now port to ARM.
So there are two sides to that: those people are going to hang on to their Intel machines longer and they'll want Intel compatibility when they finally buy ARM machines. This is important to Apple because it can shrink the pool of potential customers.