i think the last sentence in your post summed it up pretty well. if you dont fly much, dont expect to have enough miles to upgrade often?
im assuming ur most frequent route is SIN-DXB, as been reported here many times the premium loads are pretty high all the time, so chances of an op-up are minimal. i do sin-man/lgw a lot more and i've never been upgraded either....
after reading the thread about EK increasing their prices i checked the prices against several other airlines. qatar was a little cheaper but their frequencies are not as good, thai was a bit cheaper as well but again, frequencies not as good so ridiculous transit time and in past experience the flights are always delayed quite a bit and they dont even have a personal TV let alone AVOD in economy and unless you buy the expensive tickets you dont even get any miles...
its hard to complain really if EK is still pretty much the best bang for your buck...
personally what i save my miles for is not upgrades, its to get redemption tickets in J so i can use it for holidays with my girlfriend