gene pool diversity and stuff of all kinds

so cycling into the computer lab today i noticed that there are
no two bikes the same in the cycle rack outside. this is remarkable. indeed, I noticed in gatwick airport last week that (aside from little old couples of american tourists traveling around) there were no two bags the same on the whole carousel.
then I relaized that on 5th avenue last week in NYC there were no two tourists with the same camera!

And yet I notice in the conference that almost all the laptops were from a gene pool of 3 (macbooks, ibm thinkpads, and dells).

then thinking back a couple of weeks, i recall that there were no two tents the same in glastonbury.

why is that, peg, I pray? what makes laptops special??? eh?