..... I think its impossible for anyone to really know what financial position Williams Pinball was in when they called it a day unless you were working in the accounts dept.
No, public company, information is out there. Could start with this
http://media.corporate-ir.net/media_files/irol/76/76037/reports/wms_042301.pdf (page 12) and look for other information if you really want it, it is out there. Pinball was losing money, and a public company has shareholders to answer to, and saw better opportunities in other areas of gaming. Watch "TILT: The Battle to Save Pinball" they go through some of the financial losses (not in depth though).