I'm not sure how applicable this is to software. If you're making nails or something, then sure, your factory can only turn so many tons of coiled steel into nails per day. So other companies can exist that also make nails. In software, it's a little different; you moving a billion copies doesn't necessarily take any more work than selling one copy, so even if you "want to leave enough for everyone", you might not be able to. I doubt the Chrome team was saying things like "we shouldn't add tabs, that would be so bad for Internet Explorer".