Note that if copyright only lasted 10 years you could take them down but somebody else could simply republish them. The real question is, with only a 10 year copyright would you take and publish fewer photographs overall?
If the copyright protection expired in 10 years, releasing them at all would be allowing someone else to monetize them in a few years.
So? 10 years is eternity in the world of software. If some company wants to fork, say, gcc as it was 10 years ago, and try making money selling that... well, people have the right to ruin their business.
How about 10 year old Linux and not having to jump through any hoops or legal problems of TiVoizing it?
Or 10 year old iText from when it switched to AGPL? Now you can completely ignore that.
I can point to people running even older iText- they would love to update it to something more recent with no copyright protection at all under a 10 year limit.
Removing copyright protections from them would be very disconcerting. I don't want to find my photographs as postcards sold somewhere without any licensing fees paid to me just because they're old.
Consider also that the GPL and all software licenses use the power of copyright protection as the legal force behind how they work. If copyright protection was 10 years, one would be able to take any 10 year old code and close source it (and sell it) with no legal repercussions.