This game actually has pretty fun game-play, if you just focus on your own hero and doing the best you can in the situation. I mean if you enjoy playing and not just winning.
I actually prefer not having four people each constantly wanting to micro my every decision. There's a basic level of coordination you can get from just pings and guessing at each other's intentions which is enough a lot of the time. And yeah sometimes you lose because of coordination mishaps, but firstly it's not the end of the world and secondly most of that stuff is only marginally less likely to happen when stacking.
Fair enough, I can see why it would be a matter of taste. It's not about winning for me though, part of why I enjoy playing with 5 stacks is because you can coordinate silly strategies (tusk + 5 meepo snowball of death, huskar + dazzle shallow grave for 5 seconds of max attack speed), and possibly fail hilariously, without getting flamed by your team.
Even excluding dumb gimmick teams, I usually have more fun losing with fun/calm people than winning with assholes I had to mute.
It's not really that easy honestly. If you're a solo looking to get a 5 stack it can easily take an hour to get a team together out of chat, and then you'll probably have a pretty wide MMR range. Sometimes you just want to play.
I can always get a full group together in 5 mins, sometimes 10 when it's ungodly late/early in my timezone. It could take longer for you if you're in an uncommon timezone, but an hour sounds absurd to me.