Honestly, doesn't really matter how good LotV is in any absolute sense (though I expect it to be average). The game is dying. They had one shot at resurrecting competitive RTS back during Wings of Liberty, and they blew it. It was just slow decline afterwards.
SC2 is not boring. It's pretty challenging and fun to play, even at lower levels of skillset. So that's an incorrect statement. Subjective oinions.. everywherreee
It's pretty much the opposite of fun to play. A lot of its fundamentals are flawed, and in their eagerness to make the MP more approachable, the developers made it into one of two extremes: either cheese fiesta build-order poker, or boring and passive turtling into maxed armies with a single game-ending battle. Since macro is much easier, there are much fewer microable units, and counters are harder, the result is that build orders and army compositions are more important than execution, which makes for a frustrating game to play and a mostly boring game to watch.
This isn't a particularly controversial opinion either - this was discussed on TL ever since WoL release (well, technically since tournaments started using non-horrible maps, but whatever), many times.
HS is casual? Okay, why aren't you the top #1 player in the world then, since it's so easy to be good at ? Sure, it's no MTG, but it doesn't need to be. HS is VERY successful, fun, fast and enganging. It's complex and innovative. A smash hit. You might not like the game, but saying is casual is also flat out wrong.
HS is casual by design. It has some amount of competitive depth, but this is in spite of the developers' efforts. It is literally a tablet game for people to play casually during their lunch breaks or while commuting. It's painfully boring to play when you actually try to devote your whole attention to it, "engaging" my ass. There's also nothing particularly complex or innovative about it. The reason it's successful is that it has great presentation, a polished client, is very easy to get into (aka casual), and because of the Blizzard brand.
By the way, the notion of a "#1 player in the world" is pretty dumb in a game with so much variance, and I say this as someone who sat in the Top100 of the EU ladder for most of a season at one point. Getting to Legend (less than top 1% of all players, if I remember correctly) in HS is much, much easier than a similar feat in proper competitive games like Starcraft, CS or even Dota. Hell, I reckon the annual Call of Duty has a much higher skillcap as well.
of Blizzard's 
