photo.net was 1999, flickr 2004, zooomr 2006...my point is that the pie is so big the many folks can have their piece, because nobody can have it all.
about the car industry comment...most of the folks that made a so called "me-too" car company, was in the beggining of that industry, that is 80-100 years ago. Yes, its hard to make a new brand but Pegani Zonda seems to have done it in 21st century so good that it can compete with Ferrari.
With your thinking people shouldn't be programmers because there are too many of them. <br>
I will just aggree that if you can do it better then just do it.
Are you sure nobody can have the whole pie? Some domains have significant network effects, which work to prevent competitors from developing a useful service. E.g. eBay.
Ebay bought its Chinese clone for hundreds of millions of dollars, which afterwards collapsed because after moving the servers outside China the service's data were going through word filtering (e.g. during login) and there were failures...
I will just aggree that if you can do it better then just do it.