Why did Commodore put monochrome video output on A500/A2000?

[psxphill]

Probably to save money. :-)

They did ship the a500's with modulators that have colour composite, so it wasn't completely a cost issue.
 
However it might have been cheaper and easier to build 50hz & 60hz Amiga's and then ship the appropriate one with whatever modulator is required for each country.
 
It might also have been a space issue.
 
I used both the RF and composite video from the modulator when I first got my a500 and it was fine for playing games.

[psxphill]

Indeed you're right. I bought mine in Sep 1988 and I had to buy the 520 separately and this was in Europe. Only later in 1989 came the pack era as you say, and was included in the price.

Ok, yes I did buy an a500 batpack in 1989 & I assumed they had always bundled the 520.
 
But still, I don't think it was them trying to force you to buy rgb monitors.
 
The a500 was a cost reduced machine, part of that cost reduction was removing the colour from the horribly bad A1000 composite.
 
The early Atari ST's didn't have a built in modulator either.

[psxphill]

Why not?

You wouldn't necessarily get 4096 different grayscales because some of the 4096 different colours could have exactly the same intensity.