Pure 5 disappointment

Why are the headphones in the lowest price segment of Sony getting worse? For years I have carried that for its price (20-40) € were unbeatable MDR-ED 21 and 31LP. Unfortunately, there is no longer the. To replace only MDR E818LP and E828LP remained my lot are more favorable, but also sound very good for its price. I've already a lot of money spent on in-ear earphones from Shure, Beyerdynamic, Beats by Dr Dre and Klipsch. But these things are the sports options is not suitable for my ears with all kinds of cushions because they do not hold properly and is completely lost in bad seat of Bass.
And now for MDR EB20. Pure disappointment. Sounds really bad. Tinny and zero bass. Much worse than the MDR-ED12 I have bought and not like that. By contrast, sounds a MDR EB18 and EB 28 right great. I think I buy me a supply of MDR-E818LP. For sports, it is ideal because it does not have these disadvantages-Ear (body sounds in motion and loss of bass when not optimal fit). He also sits comfortably in your ears and bring a decent bass over without having to readjust constantly. The MDR-EB20 I throw them away. Am really disappointed by Sony.