What would you have the contractor do or would you hire professionals to come in and fix it. Never mind that the tiles don't line up either.
I'd have somebody do something. The grout in our BR was like that and do I have a mold problem now in there. I wouldn't be overly happy if it was my tile.
OMG. I don't know what I'd do exactly, probably depends on how much trust (if any!) you have left in the contractor to rectify it. Can't be lived with; can the tiles even be saved? So sorry you're dealing with that mess. :(
I'd request the contractor 'fix' this and make it right and if that requires a total redo and replacement of tiles then okay.
Hopefully said contractor did not get paid in full for this mess.
Having lived thru this ...
I would offer the contractor 2 choices:
1- I don't pay for the tile job and the GC demos all this out, then replaces with new cement backer board.
2- all of this grout is removed, then I see the job without grout, THEN they put in new grout that was properly mixed AND carefully finished.
If you go with option 2 please insist that, "I want to be sure this is done correctly to prevent leaks, so I insist on seeing the tile after the grout is removed. Otherwise I have no way of knowing if the installer chose to put a thin layer of grout over this. I am willing to give you a second chance, but only if this condition is met."
IMHO - anyone who is this sloppy is probably also very lazy, which is why that middle step of "I gotta check to be sure you removed the old grout before you apply new" has to apply.
In real life, I'd say it depends on how close you are to the start or the finish of the project. If you're near the start, then the contractor still has an interest in you being happy enough to make your next few payments on the payment schedule, and so he's going to have more motivation to make you happy.
On the other hand, if you are nearer to the end of your project, only a few payments left for him to collect, then he has far less interest in making you happy enough to hand over your money. I only say that so that you can set your own expectations and demands that it be fixed.
I'd take plenty of photos, determine in your own mind if you trust this contractor to fix it to your satisfaction, and if not, then absolutely stop making payments until you have an estimate from someone else what it will cost to rectify (perhaps tear out and re-do costs?)
So sorry to see that photo and what it means that you're going through. Ask the contractor if he would like to have his own home left like that, or if he'd expect it to be corrected.
Oh my! That isn't just a bad grout job, there seems to be something else going on with the tile. I think EngineerChic has given you good advice. This is a shower?
That's what the end results looks like when I grout. Which is why I hire out grouting. Totally not acceptable or workmanlike. Dunno that I'd trust the same person to make it right either.
We had Dumb and Dumber do some basement waterproofing in our last house. They had to come back no fewer than 6 times til the job was finally done right. Everything they did made the leaking worse! We should have run away after the first screw up...