Well D1 came out in 96, meaning development for it was at least two years or so before that. So than what game in the rpg genre (we will call it) was popular around the mid to early 90's? PC games were'nt as popular then as they are now so of the few that were out then, I doubt any had a large enough audience to interest Blizzard into copying any ideas from them.
What about consoles....SNES, and then PS1 a little bit later on, were the standards then. Though, I can't think of any rpg type games on those systems that used the same isometric bird's eye view that D2 uses. The 'Strike' games (Airstrike, Urbanstrike, etc.) as I recall used a similar viewpoint, but were 'action' genred games, with interfaces that were nothing like what would be used in these types of games.
Afaik, the D1 interface was pioneered during D1s development, and than later on passed down to D2 with a few tweaks here and there.
What about consoles....SNES, and then PS1 a little bit later on, were the standards then. Though, I can't think of any rpg type games on those systems that used the same isometric bird's eye view that D2 uses. The 'Strike' games (Airstrike, Urbanstrike, etc.) as I recall used a similar viewpoint, but were 'action' genred games, with interfaces that were nothing like what would be used in these types of games.
Afaik, the D1 interface was pioneered during D1s development, and than later on passed down to D2 with a few tweaks here and there.
D2's interface was obviously based off of D1s.