story
* portia doesn't work in 3.x because of scrapy, twisted and scrapely;
* psdash - developers don't care;
* jasper-client - developers don't care;
* ansible - Paramico was not ported when development started, now it is a big task to port ansible;
* scrapy - depends on twisted;
* heartbleed-masstest - developers don't care;
* planout - developers don't care;
* beets - not sure what's the reason, either some dependencies or developers don't care;
* reddit - no reason to move for 3.x for a large codebase which is not a library;
* salt - docs says it needs Python < 3 (maybe the reason is similar to ansible's);
* pacemaker - developers don't care;
* pyjvm - developers don't care;
* sentry - large codebase which is not a library.
That's not bad (12 trending packages have 3.x support, 13 don't). But clearly something stops some new packages from starting in py3, and many packages that people find interesting don't work in 3.x. I think that the only way to improve this is to help porting "base" packages that ecosystems depend on; just providing alternatives is usually not a good answer.