Are they buying it up to kill it or phase it out? Seems like corporations never do anything like this to the "good" of the community, it's always bad. I'd love to be pointed at exceptions where a megacorp bought some small relatively benevolent project and then didn't squeeze all the profit out of it and leave it for dead.
I would guess they want to keep it - there are a lot of company advanced engineering projects run on Arduino and when those prove useful (most don't) the company starts looking for how to make it production. Thus having Arduino as a push to their chips is a useful in to more companies.
Of course companies change directions all the time. I wouldn't surprise me if the people who bought Arduino believe the above vision, but there are other political factions that will try to kill it.
Google bought Android, but did not kill it. Same with YouTube. But, I admit, there are a lot more examples of the other way...
Yeah it's not totally dead. But they definitely killed what made Android great. Now it might as well just be iOS. Same boring ass phones that do nothing well but install spyware apps, consume content and scroll through social media. Just more trash for the landfill.
Killing Arduino doesn't serve their interests based how many as-like boards there are. This is more akin to Microsoft's acquisition of Minecraft. Quick and easy way to get people in the door through recognition and a large user base.
I don't think it's malicious, it's just that Qualcomm offered a big payday to people who have been working on the project for a very long time and are probably on the verge of wanting to go something else in their life. And then they're gonna force them to navigate the Kafkaesque bureaucracy at BigCo to get an approval for every blog post, conference talk, etc. Expense reports, headcount planning, performance management, you name it. After a year or two, they're gonna be thoroughly cooked and leave.