It is of no surprise that so many go under. The criteria used seems to be one of copying other businesses because they seem to be doing well. Doesn't anyone pay attention to market size? That is the number of buyers and sellers available for the product?
The Costa del Sol is a small market and the volume of business it can support is limited to its size, which is further reduced by language and consumer level boundaries.
The more competitors the more the size of the market is reduced with the result that a buyers market is created. This is when the buyer dictates the price and competitors have to reduce prices to be able to sell.
Add to this the economic crisis and cheap is never cheap enough, there is always someone cheaper. Quality of product and services is then reduced and even lost to cut costs.
So what makes the fish and chip shop owner owner think that he can become another publisher despite the excess of publications around? What makes a bar open near to or next to another? take part of the clients away so neither can make a living?
If you need to go into business do not commit financial suicide, look for the right opportunities, research properly and be sure you can provide the right quality product at the right price.