I think a lot of content on steemit is entrepreneurial. May be if people knew that, they'd be using the tag more often.

I agree with you there! I've even seen persons post links in our post promotion channels and don't even have the INT tag on them, despite there being a notice at the top of the channel specifying the need to do so in order to qualify for rewards. :/
Perhaps advertising is needed among more established groups on the STEEM blockchain, for as your suggestion,

Tie up with other tribes?

Can prove to be beneficial to the STEEM community at large, via more entrepreneurial bloggers getting recognized and appreciated though jointly run tribe initiatives like contests, giveaways etc.

Have a dedicated curation team?

Yes, I think this may be something that we definitely need to consider. All of our existing team members carry out tasks that are more in line with their individual passions/natural inclinations, and none were hired as 'curators' since it was initially intended to be a group run effort.
However I think it may be time to reconsider this approach and bring on some members who will be tasked with cleaning up the INT tag, specifically appreciating good posts in accordance with the community guidelines, and warning/downvoting repeat spam offenders.

Thank you for the continued support & helpful insights, as always your participation in our weekly quests is greatly appreciated. :)