In this hypothetical situation, this would be like getting two new tires on your pickup, but when you go to pick it up they accidentally put two 29" bicycle tires on your rims instead of two 29" light truck tires. They don't see the problem and expect you to drive away like this. You'd be like yeah, hmm, I see how that could be confusing, they're both 29" tires after all. no big deal, you guys take care of this, OK? you guys are totally competent enough to put the proper tires on after we've had this issue and learned from this mistake. carry on.

this would be like your plumber accidentally substituting some 1 1/2" galvanized fence post for 1 1/2 galvanized iron pipe and not noticing the difference, your electrician substituting some shit like this as a ground wire because they're both wire coated in green plastic https://www.homedepot.com/p/Everbilt-5-32-in-x-50-ft-Vinyl-Coated-Wire-Clothesline-Green-65025/202957532 and you'd be all like, yeah, no problem, I trust you to finish the job properly.

does this hypothetical drywall/tile guy just dump all his materials into unlabeled home depot buckets and drive around not knowing which of his 7 buckets is 90 minute mud, which is easy sand, which is thinset, which is grout, which is fertilizer for the roses at this one customer, this one bucket of diatomaceous earth for his swimming pool gig, and this one is calcium chloride, for when its snowing...

yeah but this would be the kind of mistake that betrays some kind of deep lack of understanding on the part of the guy doing the work. if a contractor did this I would have an honest suspicion the worker is literally illiterate. as a diy project mistake its no harm/ no foul.

lol if you hired someone and they made this mistake you should 1. not pay them. 2. tell them to gtfo immediately without touching anything else. 3. never call them again.

edit: i guess you guys think I'm being too hard on OP. its a DIY project, its not a big deal that he made a mistake and it should be easy to fix. on the other hand if you hired this out and the contractor made this mistake: It's honestly unforgivable that someone claiming to be a professional either couldn't tell the difference between thinset and drywall mud or didn't know they couldn't substitute that. they are really not similar enough in texture or appearance that anyone with any experience would make that mistake. even worse is if they didn't know the difference: that would mean that not only have they never done this before, they didn't even bother spending even 10 minutes educating themselves on how to do this job before they showed up. they would have known they couldn't use drywall mud after watching one video on youtube on tile before walking through the door.

bro 1. that has no adhesive of any kind in it.

2 its called "mud" because in reality ready mix joint compound is literally a fine white mud. it is a mixture of water and particles that can harden by drying but can be softened again by water. aka literally white mud.