What do you do if the adhesive is in the written spec of the job. ?
I work for 2 major contractors tiling factory units, I have done so for many years and they actually spec tubbed adhesive, never had an issue with tiles falling off.
I recently tiled a bathroom , again for the council which had in the spec...tubbed adhesive !. 4 days after I finished the plumber broke 3 tiles because the numpty drillled with the hammmer action on. It took 2 hours for me to remove and replace the tiles, which completely destroyed the dabbed plasterboard. I redrilled the holes for the plumber this time !
Now this may seem as I am for the use of Tubbed adhesive, No not really. Bagged adhesive...good bagged adhesive has a better feel to me, it can be used to bed up bad walls, it works out cheaper in the long run, you can get fast or slow setting adhesives.
Maybe its because people are too lazy to mix their own adhesive up but if you are using a slow setting adhesive then you are only going to use 2 mixes a day on average I would have thought.
Adhesive manufacturer ready mixed adhesives because their is a market for them and all manufacturers want that share of the market. You will find that a lot of the manufacturers also make ready mixed adhesive and grout in one tub !!!......Its their business !