• It distracts people - they could be too busy doing their emails/surfing the net that they miss their stop - they would then have to transfer trains/buses to go back a stop going the other way, or they would have to walk (which could make them late)
• It would cost the Public Transport Authorities lots of money to install wireless routers + pay for the internet - you could maybe research the number of trains/buses there are, how much each wifi router would cost, and see what the rough total cost would be
• It would encourage people to go and sit on a train/bus purely to access the internet - this would clog up the buses/trains and mean that there might not be space for the people who ACTUALLY need to go somewhere
That’s all I can think of at the moment, but I’m sure others will have ideas.
P.S. For next time, I think that the place to post this would have been in the CAFE forum on this site.