Msafiri said:
Visa regime is based on risk profile of travellers - most developed countries have a visa regime for 3rd world countries because a high percentage of their nationals don't leave when they visit or transit the country. This is via overstaying or making asylum/ refugee claims either unfounded or true. The Netherlands is unusual by not imposing this transit visa requirement - this is likely business driven by making Amsterdam Schipol a key transit hub airport especially for travel from North America/Europe to Africa/ME/Asia. I personally find Schipol airport well laid out and convenient with ultra fast transfers.
Msafiri, you are right, however if governments really want to keep track of travellers, they can with just the airline data they have. Visitor visa is understandable, but in transit that too for few hours? Even with transit visa, if people want to disappear they can, does happen.
Schipol wants to be key hub, however competition is tough from Paris and Frankfurt, if Heathrow gets third runway and 6th terminal, no way others can beat it in near future. Drawback of Heathrow is travellers will need to make their way in between terminals, but then they have this new Personal Pod Rapit transit system being phased out.
Schipol is good alternative, I would say, people who need transit visa must start looking at flight thru Schipol to eliminate the transit visa stress. Also flying thru some far eastern countries don't require transit visa.