There is a way to use a cement mortar mix of 3 to 1 provided they use an additive which is called Tile Grip most hardware stores have this priced around P500 per bag, mixed with a one bag mix of cement you get the equivalent of 5.2 bags of tile adhesive so it works out at around 50% less in price, but there is more to tiling than just the adhesive, 1) did they have all the comb lines in the adhesive running in the same direction? 2) did they vacuum the area to be tiled? 3) did they wet the concrete floor immediately before tiling? likely you did not get even one out of three with No 2 never being done and perhaps they even soaked the tiles before laying which is a big No No. I would not consider that house in the Video to be small at 250M2 plus another 20% added on with the garage? in my view it is massively oversized? In the Philippine handbook of good building practise it recommends never to have parallel walls greater than 3.5mtrs apart, for obvious reasons smaller compact rooms have greater resistance to quakes, The big dumb open plan US design of the Living, Dining and Kitchen area all in one makes no sense to me and also the view of the contributors of this Philippine Handbook they were a mix of professional people from a mix of countries more advanced than US that have experienced natural disasters.