Dtilt isn't a move to use at neutral, but rather to catch him with once you get in. Say we manage to get in with a grab and release him offstage. 90% of the time, Snake will just recover high, so you follow his landing and catch it with dtilt, putting him in a terrible position offstage.
I dunno if this is just me, but I don't really have an issue with getting hit while dodging nades, unless I try to dodge aggressively and approach Snake while doing so.
I can understand what you're saying, since I've felt that this MU is booty too at times. But for every time I have a horrible time in the MU, I do things like go close with MVD/Ally and I wonder whether or not I was just playing wrong or if they're just not playing the MU optimally. I have too many widely different experiences with the MU to accurately say which is more valid, so I just go with what happens more often, which is me going close then not being able to kill.
I've always thought Marth was even, since I practice against Marth all the time. I can understand -1 though and I'm okay with it. I think the MU is hilarious in certain situations though, and my main practice partner cringes every time I tank an attack with DJ.
Dtilt when we get him? Frankly for every Yoshi main (something I started noticing I think at the start of this year) all of our basic combos seems to be approaching with Bair and if we land it we immediately hit with Utilt.
Anyways onto following his landing... he'll either B-reverse once or twice or just Bair us if we're waiting underneath him, which is why when they choose the Double B-reverse I just tend to throw eggs at him hoping to get more than 15+% off him instead of getting him with a Dtilt for 5-7% (maybe even less if we hit him with the very tip), hell I'd rather toss eggs at him even if he did none of those things instead of D-tilt. That and even if we hit him with D-tilt, you're thinking he'll be holding down and end up DI'ing underneath the stage, he'll just UpB again anyways and be safe depending what direction the snake was holding. It's very situational Delta.
And it's not just you, I'm not saying grenade tack damage isn't that crippling. It's just annoying and even if we only get hit from 1 out of 5, it's still extra unneeded damage since we can't blindly go in and possibly eat a U-tilt to the face, we still need to wait for an opening but until then it's gonna be us jumping for 10 or so seconds till snake approaches or we feel like risking it. (and depending where that detonator is, that time could possibly screw us up especially if it's BF YI:B or Smashville. I seriously hope people don't take Snake to YI:B anymore.)
Also, I'm sure it's just Ally/MVD sometimes forgetting how Yoshi works, then next game they have you downloaded and have the gist of how he works and plays a bit different while still occasionally getting caught in your tricks.