As if Rockstar couldn’t do both with the fastest profit generating piece of media of its decade.

The game literally set records for profit generation against all media types on release, they could have had 10 teams working 10 different DLC’s simultaneously.

https://www.gamesindustry.biz/gta-v-is-the-most-profitable-entertainment-product-of-all-time

It was a choice to not focus on single player, and not a bad one.

At the end of the day, the content’s longevity goes up when integrated with GTA online and would increase the activity count, thus profitability of online.

It’s an AAA company working for a profit, not an indie title passion project.