Two more reasons -
I submit that any arrangement using a pedal would be more complicated and involve more parts than any arrangement using a simple friction catch; both of which would translate into more expensive. And we all know how manufacturers feel about higher manufacturing costs.
Also, any arrangement using a pedal would be difficult to combine with a reversible door - a feature that most manufacturers strive to offer on both dryers and refrigerators and I daresay the customer has grown to expect.
lawrence