I have played Blizzard titles since WarCraft 2 and when I first tried StarCraft, WarCraft 2 felt outdated. The graphics and animations were so much better. It was a new generation of RTS. That's what I thought.
Jump to today though and StarCraft is a bit unplayable because of its ancient unfriendly UI. Have to fight the interface instead of the friggin opponent!
To make a long story short, StarCraft 2 is on my "3 most anticipated games list" and it's probable it's nr.1!
Destraex
StarCraft was made in 1997. The graphics technology of those days were quite limited to when Company of Heroes were developed.
But Blizzard have their own artstyle. It's a bit over-the-top, not so realistic which IMO is fantastic.
About size & scale, Blizzard puts gameplay above everything else (as all gamedevs should). Having gigantic cruisers that cover half the screen would obscure the view. Also, Blizzard is aiming at making StarCraft 2 the next E-sports game and that means that there can't be stuff in the way which covers the players vision.
You can make big armies. You got a maximum of 200 population. That's like 50 Marines, 10 of the other infantry, 3 Ghosts, 15 Siege Tanks, 10 Hellions, 3 BCs, 15 Nighthawks and the rest workers.
If you ever manage to fill your 200 population cap though, then you're not playing as good as you can.
If however, you want Supreme Commander like battles then the StarCraft series are not for you. But that's how things are. Some like C&C, some Age of Empires/Mythology and some the craft games.