Yes, my opinion is that now that following tags is out (and that's something I've thought would be good for quite a while), that we would be better served by allowing multiple tags on a post. The reason is that a singular tag functions as a community organizer, while multiple tags can transcend a singular community and hopefully bring groups together. I am lobbying to have a character limit in the tag field and nothing more. That limit would also be arbitrary, obviously, but the other option is infinity, and we have to stop somewhere. Some happy medium probably exists.
Keep in mind that keeping ignore around opens this up to (even accidental) abuse. If I ignore #atheism and someone posts a #cosmos video that another person finds areligiously inspiring, I won't see it, despite loving the spiraling shapes of galaxies! I'm tempted to suggest a probabilistic ignore, if the votes for a particular tag exceed 25%, say, keep it out of my feed (Balancing this with the number of users I follow suggesting the post to me, perhaps). But I also have a tendency to suggest overly complicated solutions, so pick and choose what you think is actually decent.