Kitchener's lack of free parking is essentially Metrolinx's entire reason for wanting to construct the Breslau station.
There are actually quite a few GO stations that have no parking, and another few that have "limited" parking.
No Parking:
Union
Danforth
Bloor
Exhibition
Kennedy (technically there is paid TTC Parking here, but no formal parking for GO)
Kitchener
Hamilton Centre
Kipling
Stations that I would say have limited parking (i.e. small parking lots due to constrained land areas), more in line with a typical Metra station:
Mimico
Long Branch
Stouffville
Agincourt
Markham
Centennial (there is a parking garage here but it is fairly small, and essentially no surface parking)
West Harbour GO
NIagara Falls and St Catharines
Newmarket GO
While I agree that the big stations with thousands of spaces are the busiest stations and how most GO customers experience getting on the train, I would argue that smaller more pedestrian scale stations are far from unusual for GO.