Actually - I took a closer look. The explanation is perhaps simpler.
Tide doesn't make a stand-alone fabric softener. Or if they do - amazon doesn't seem to have it? There's TIde, and Tide with Fabric Softener, and Tide with a dozen other variants - but nothing that's not detergent plus.
So - no point in differentiating. The little Ad-man in my said says "We don't sell mere laundry detergent - we sell Tide!"
To put it another way - did you ever go buy to buy detergent, and accidentally buy fabric softener? Yeah, me neither. So - the concern is perhaps unfounded.
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.
To any future monthly posters of SQ threads, please remember to add the "stupid_questions" tag.