Illustrator :: Convert SVG With Filters To AI Causes Rasterization

Working: Opening any normal SVG file in Illustrator -> saving it as AI, exporting as PDF, printing, anything. Behaves as expected.
 
Not working: Doing the same with a SVG file that uses filters. If the svg was not created in Illustrator (with preserved editing capabilities), it will remain rasterized in Illustator, no matter whan format you convert it to, export it to, or if you try to print it.
 
If you however remove the filters from the SVG, create a new AI file, paste the SVG inside, and then import or recreate the very same filters from inside Illustrator, then everything will work just fine. Clearly there's nothing wrong with neither the filters not the rest of the SVG, but just with Illustrators SVG importing capabilities (dealing with SVG filters).aside from manually importing/recreating the SVG filters from inside AI? And when does AI plan to add decent support for importing SVG created in other programs?
 
Example:

1. Download this SVG: URL...
(disclaimer: not mine. You can also use any other SVG with filters, as long as it's created outside of Illustrator).
2. Open it in AI.
3. Export to PDF, zoom in -> it's rasterized.
4. Create a new AI file, paste the SVG in there, manually re-create/import the SVG filters.
5. Export to PDF, zoom in -> WORKING.