My main point was directed at people who are new at this. I've been there and I can smell a bad partnership right away (and most of them stink). But when you're new at this, it's an easy trap to fall into. Big companies dangle their customer base in front of you ("Wouldn't you love to get your product in front of our $HUGE_NUMBER customers?"). When you're new at this and deep in the slog of trying to grow your startup, that's a hard thing to resist.
(btw, I don't consider having an affiliate program part of partnerships)