Why is Unity's merger with IronSource angering developers?

gamedeveloper.com:

Yesterday's news that engine maker Unity is merging with IronSource in a $4.4 billion deal triggered a slew of negative reactions across social media. Much of those responses, which ranged from anger to resignation, came from game developers who use Unity to make their games.

We cover a lot of merger and acquisition news on Game Developer, but few stories have raised as much ire as this development. It turns out plenty of developers are familiar with IronSource's somewhat sordid past. While the platform has most recently been a fairly run-of-the-mill advertising platform for mobile apps, it has a brief history of being affiliated with malicious adware.

But that's not the only reason developers are upset. Unity's merger moves are the latest in a series of acquisitions and business decisions that have left some customers feeling left out in the cold. As several sources told Game Developer, it's not just that Unity is pivoting toward advertising revenue as a core part of its business, it's that the steps it's taking leave its customers on unstable ground while making their games.

Then we woke up and saw that Unity CEO John Riccitiello called some developers "fucking idiots" for their resistance to consider and implement monetization earlier in the development process. That probably made things worse.

During an interview with PocketGamer.biz, Riccitiello praised the idea of creating a "live creation engine," that can "provide critical feedback as early in the creation process as possible, and starting that conversation with potential users at that point." 

When PocketGamer's Khai Trung Le pointed out that implementing monetization earlier in the process "has seen some pushback" among developers, Riccitiello made the comparison to