He obviously didn't use spacers.....

I have ceramic tile and every tile is the exact same size. I know this isn't true with stone and some other materials. The grout will make this less noticeable if at all.

We have only used ceramic tile too and when my husband installed it, he used spacers and it looked perfect! I do not know what to say.

He used spacers. He just didn't use the ones that go at the corners to make sure the corners are aligned.

The tile is 16x16 ceramic tile. The tiles are the exact same size. I laid the same tile in the master bathroom 4 years ago (we had a lot left over), and I used the corner spacers that have a cross on one side and line on the other. My corners were perfectly aligned. I guess I just should have laid the kitchen tile, but with 3 jobs, a 2 year old, etc I don't have the time...

In that case it is time to either redo or negotiate a considerable amount off. If you have them redo it do you have enough tiles? Can you buy more? They may break some in the process.

The tile was laid by a GC who said his professional tiler would be laying the tile. At this point they are 2 months over the time period for all the repairs, and it took the guy a WEEK to install the entire kitchen. And I know the kitchen which is only 10x14 should have taken a day at most...

I had a different contractor come in today to look at finishing our cabinets, and he said that he could tell just from LOOKING at the floor (he didn't even walk on it) that it was not prepped correctly and that it was not completely level...

I do have enough tiles if they have to redo the floor; however, I had wanted to save enough to redo a hall bathroom with the same tiles next year. We really like the tile, and just thought the house would look more cohesive if all the tile was the same throughout the house. Redoing the floor in the kitchen probably would give us enough to do the bathroom tile later.

Is there a way to fix what is already down without ripping up all the tile he laid in the kitchen? Or is it a matter of just having him take it all out and start over?

Oh, and he didn't even remove the rest of the baseboard or door trim when laying the tile. They had already removed on entire section of door trim when they tore out and put in new drywall, but left the trim on the other side of the door since drywall was fine over there.

So when the GC's tiler cut the tile he just curved the tile around the door trim. And then a small section of baseboard was still on, and instead of removing it he cut the tile around it...

My goodness. This is not a professional tile setter your GC is using. It needs to be redone. Curving around the doors is pathetic. I would have GC bring in a new tiler at his cost. I'm sorry this has happened. Crazy how incompetent people can be.

I don't think your floor falls into the category of disaster, however it does show sloppy work that would really irritate me. He did use a tile leveling system so, in theory they should not be uneven. The inconsistent tile spacing, and poor corner alignment would really annoy me, and the approach to the trim would piss me off. Why did he cut a tile with such a large gap against the cabinet in the first picture?
Some of this sloppiness can be fixed without a tear out ( tile work around trim, the odd sized gap against cabinet) , but fixing the poor spacing or misalignment could be very tough. Your tiler should have done better, but your GC should have also stepped in during the tiling to say some of this is unacceptable.
What exactly was the other contractors concern about the inadequate prep work for the tiling? If there is another unseen issue...that should be addressed.

If the tile is uniform and tile is the same size... as Cancork Floor said, this should be corrected.

If you purchased your tile at one of the box stores, this is a common issue because the tile varies in size and spacers or anything else installers use it will not help.

I think you have two choices. Either have them redo it at their expense and you pay for the completed job or don't have the redo and not pay for the labor and hope with the grout it will be less noticeable. The most disgusting part of this whole thread is that you laid the same tile in the bathroom and did a better job than the professional.