I think you have to take a closer look. Ming barely does any damage at the beginning of the fight. Misses her Qs and her Orb only hits Dehaka for a small amount of damage. The only damage she does against Anub is with her tickle beam. The reason why Anub was nuked is the focused damage of the other 4 members, with Malth propably doing biggest part.
Almost no bruiser can survive a full five-man collapse without support. If you ask me he was focused quite a bit at the end of the fight. He had both enemy Dps and Dehaka on his trail and after that Dehaka, Reghar and Anub. All of which can do a good amount of single target dps.
Zul’Jin propably beats most heroes in a 1v1, because of his ridiculous single target damage. Doesn’t surprise me, that a single target AA hero beats Malth. It is his natural counter after all.
Isn’t really a 1v1 if teammates show up for help, is it? From my experience Blaze shouldn’t win the 1v1 because he barely does any noticable damage (If Malth isn’t standing in the fire). A lot of Blazes Abilitys can also be baited and dodged.
I am actually curious how you do it, because my general experience is the opposite. And like you
it seems ludicrous to think that I haven’t encountered good solo lane opponents since his rework.
Little Edit here. I did notice Malth to suffer a bit in 1v1 in mid-lategame, if the enemy commits to a stronger 1v1 build. Bruisers like Imperius, Dehaka and Thrall did bully me out of the Shrine on Dragon Shire. I have however yet to see a tank do the same.
As for the OP I can say, that I only agree with the point that he is squishy, atleast for a bruiser. He does however have a lot of mobility and can easily heal himself up if he is not the target of attention.
If I were to give Malth a buff it would propably be a return of the armor of TS, to make Malth a little bit more sustainable in the middle of everything.