The answer is that lane dominance benefits far more versus less skillfull opponents. Ryze is a lategame champion so in meta where games tend to last around 20-30 minutes he just doesnt have enough time to stack his .
Also in my opinion you really benefit from at the later stages of game.
"Better get that cheese kill from enemy midlaner making mistake instead of farming until the end of laneface."
Ryzes Q is his most spammable ability thus does most of his dmg output. Q takes 6 "leveling points" to master instead of normal 5 of basic abilities. Q can be used without cooldown reduction after using either W or E . Because the CD resets after using W or E (we will talk about R later) you should if possible always start combo with Q so you can use it as many times as possible. While Q is the bread and butter of Ryzes dmg, it will be maxed after E because of reasons mentioned in E paragraph.
Ryzes one and only CC tool. If used after E
Maxing E before Q is better because e helps you farm and do lane harass. Maxing E also scales your Q dmg percentually so it's like hitting two birds with a one stone.
You should still take few points into Q early (as seen in quide above) since E is lot more mana hungry and will deplete your stamina faster than you think. Mana cost scales up while leveling unlike .