Citation needed.
If my competitors want to waste time and resources hiring people to create 3-4 versions of the same app for different devices/OSes, I gladly welcome it. I'll be a well established incumbent by the time they put out their MVP.
If I can solve an important business need, my customers don't care if I use 120mb of RAM to do it. They certainly don't see it as "disrespectful" if I can save/make them money in the long run.
However, the problem is that you end up with apps that behave differently, miss features, and have different bugs across platforms. Drives people crazy. Just one example: 1Password 7 for Windows shows different search results in a different order compared to the Mac app. Obviously it could be fixed but then a different issue pops up somewhere else.
Instead of adding new features we spent time fixing (making?) various bugs in different ways.
The new 1Password 8 still has a ton of platform-specific code but the core is the same across all desktop and mobile apps. It allows us to get the new features out faster and also spend time on platform-specific code.