I would say it is because a) there is a lot of money to be made and b) Moore's law forces one to move fast to corner a market because one can almost guarantee that someone will disrupt it within a few years.

Early customers were knowledgeable about this. Because of that, they accepted (partial) failure of products in exchange for earlier delivery and/or lower prices. Those customers, in turn 'educated' the masses to accept crashing products.