" where are the days where a dev would optimize his code for reasonable memory usage ?" For most common applications being memory frugal is not valuable for the time it takes to tweak the code. What is more valuable is programmers' time both to initially write the code and to maintain it. So code that is easier to understand and follow wins out over highly optimized code. If this means a few extra megs of ram it probably will not be noticed by most users.
Also, remember the mantra the cheapest upgrade to a computer is to add more memory particularly to a desktop.