Probably being butthurt about OpenMapTiles and MapTiler "stealing" their business? But then again, Mapbox, judging by the buzzword-laden landing pages and focus on "contact the sales team", seems to be catering to the corporate big fishes. (I may be mistaken though).
Another thing is that Mapbox is owned by SoftBank which hasn't had a good year so far and has to recoup WeWTF losses somehow.
And thank you for the link - I wasn't able to unroll the thread in Threader. I'm probably out of the loop if Twitter has broken their API.
That makes sense. I forgot about the SoftBank investment.
Still, looking at the thread, I wish people would be less sarcastic and vitriolic when pushing for the spirit of open software to be upheld. Ideally, it should be presented as a win-win, instead of a how-dare-you.
There's somewhat of a resentment at Mapbox from the OSM community that they hide the required attribution [1] behind an "i" icon on mobile. This information besides satisfying the licence requirements serves as a "powered by" acquisition channel for OSM, like discussed earlier this week on HN [2].
That said, Mapbox does offer some QA tools for OSM mappers to use, so the net result is hard to judge.