236 isn't that low. If you ding lvl60 you'll be something like ilvl 120 or so. You can buy a full set of 226 gear in ZM for anima but that isn't enough to get into heroic (need 230 to que) and isn't high enough to get into a m+ pug. Even for a +2 people want 270+ ilvl. How are people supposed to get to that ilvl without normal and heroic dungeons? M0 gives 262 and they hotfixed lfr to require 235. Also ques aren't that long. normal and heroic ques are like 10-15 minutes for dps and maybe 2-3 minutes for tank and healer.
In addition I had lots of normal and heroic dungeons on my alts that went horrible with half the group getting wiped to mechanics. House of plagues is the worst one because there are one-shot mechanics that will kill new players and most people I played with did like half the dps I did. Most people are bad and wouldn't survive in m+. Requirements for m+ pugs are already insane and if you force more players into the system that can't play and can't outgear the lower levels, it'll get worse with even more insane requirements.