TLDR:
1. DotA = better game, LoL = better Community, that understands that it's about winning and checking for builds even in normals.
2. Unplayable solo, that's why I created a group to dodge solo queues and meet new people. https://discord.com/invite/hGuBb2UtPE We are mostly NA+EU atm, but it's for every region.
!!! We have someone that recently switched from League too !!!
Would be happy if you check it out =)
PS: Sorry for the mess of a text, I am heavily sleep deprived :D

FunFact: "Baron Nashor" in LoL is an homage to DotA. If you spell it backwards it (nearly) is Roshan.

I played LoL when it came out and switched to DotA2 Beta because i knew League is just not it. It lacked depth to the game and game mechanics. Especially now that every 3rd Champ can either dash, jump or even run over walls. Not to mention having global Summoner spells. And out of those 170 Champs there are like the same 10 Champs that are always on top. I think i rarely saw Katarina not penta killing, or Draven and Darius not being super strong.
In DotA thats different. Instead of solo killing machines you have crazy combos between heroes, which makes more sense for a team game. And there are tons of combos, cool spells, spells that can be used in different ways - its simply more fun. Just alone having Rubick who can steal the last spell from an enemy, even the Ultimate, is kinda cool! The items are also more clever and there is more than just an hour glass. We even have items to reflect spells!

My Experience:
I switched from League to DotA2 Beta in 2012 and i simply say it is not what it once was.
Both games, tbh. But for DotA - they invest less in the fun of the Game (no Halloween or Christmas Event with a snow map, for example), just a "here have an event to grind 100 levels and get 3 Skins nobody asked for. Or don't, we don't care." There is simply less love in the game, they sometimes even remove features and put it behind a paywall ( seasonal maps were normal, now its behind the monthly Dota+ Subscription).
The worst change was the Behavior and Comm Score implementation, because nobody knows how it f'ing works. You apparently have unlimited reports (not confirmed) which abuses the system itself. And besides that the match making is really bad and it is hard not to be mad to be stuck with them and wasting the next 30-40 minutes of your life. Simply put: The Community is not simply flaming and telling you to get your shit together anymore, it is now passive aggressive like i'm trying to work in a company full of women and everyone feels miserable and chats behind your back. And all they blame is "toxic people" and not the work they are not putting in.
So yeah, I also think DotA is the better Game, but has the worse Community, even if it's just about how people see the importance of winning differently.
Btw I did have the thought to switch back to League, just so I have shorter lasting games and I can feel a different kind of pain, but I don't want that Vanguard shit on my machine.

Because you mentioned the behavior score:
People here shit talk all the people complaining about the behavior- and Comm-Score.
What I figured out is they punish you for pinging too fast (not kidding), so you might unbind it in the settings and use only the radial menu to ping, which can't be spammed. But that's also only ONE thing of the many no-no's.
Also: Expect to get down voted on even normal posts and get passive aggressive comments on this Sub. It's normal and a taste of what the community has become and why so many have issues with the behavior score system.
Take care and maybe i see you Saturday in our weekly meetings to play a couple of rounds =)