Eh. The only reason why HotS has a decent new player experience is because it's a new game. All games start off as this 'AMAZING' thing because everyone fricken sucks at it. No one knows what they're doing outside of basic stuff. To make it worse though is that HotS doesn't have much of a 'meta' and blind pick chooses between different maps, which your champ may or may not suck ungodly bad at that map. Like, say, if you get a team with limited wave clear on the spider maps or a team that doesn't synergize well heroes-wise on the raising golems map. You can get heavily boned and with the game being brand new, barely a couple months old, everyone SUCKS at it so no one can really judge. Last time I played, just before they released it out of beta, there wasn't even an ALL chat, which removes a huge level of toxicity since the enemies can't patronize some one for sucking either. With an All chat, people have access to 9 different people insulting them. Without it, there's only 4 others.
League used to be very welcoming to noobs back in S1 and early S2. S2 worlds put LoL into a whole new level of playing field though. Popularity shot up so much that there was a flux of people watching e-sports and deciding to play the game, which also came with people making new accounts because of being stuck under 1300 ELO because they flunked their first 10 games in ranked, or they got temp banned for being toxic, etc. Players with some understanding end up at the bottom and berating their teammates while the game's popularity attracts the disgusting crowd. Just give HotS a year or two when it really hits the competitive playing field and actually has a nicely sized roster of heroes with more unique abilities. It'll attract the crowd that everyone hates in League and it'll become to new popular thing because the damn thing is stupid proof. Just look at the system. You have 3 abilities by level 1, which makes people happy since there's no wind up time except on the ultimates. Then there's the fact there's no items or skill points, you just choose specific boosts to certain abilities or a clicky. It's all cookie cutter stuff with very limited variety in what you can do, which will be its downfall.
Games that are too easy will end up failing. In Mists of Pandaria, when Blizzard took an already very easy game, they made it even EASIER and they ended up losing about 5mil subscribers in just that expansion alone. Easy games attract a certain kind of crowd that can turn incredibly toxic in an instant. The one thing I can say about DotA 2 is that it doesn't have the toxicity League has, because it's not as simplistic or user friendly, so the toxic baddies who think they're Billy Badass are usually scared away, though it makes elitists more common. League is complex and user friendly, so it has elitists and it has Billy Badass wanna-bes, which makes for an awkward form of toxicity. HotS will soon get the ones who like the overly easy games and with how poor the matchmaking is, the community it doomed unless Blizzard works quick. Through my own experience with Blizz? They're not known to work quickly. They're slower than Riot. Hell, they make Valve's work on Half Life 3 look quick.