Major conflicts exist between Steam and the end-user’s computer. These problems include but are not limited to: random internet drops, incompatible with many firewalls including the very common/stable ZoneAlarm. Steam is also incompatible with a wide array of virus scanners and widely available software applications.

Many people have complained about incompetent Valve – Steam support staff. Suggestions from support generally involve uninstalling incompatible software. This support feedback, if you even receive support, can take months to receive.
It is a manufacturer’s duty/obligation to ensure its software is compatible with commonly used applications. Yet, Valve – Steam employees seem to neglect to take responsibility into their own hands, instead choosing to blame the end-user for having incompatible software.