ok, people should only use it if they want to. The corollary to that is that there shouldn't be coercion to use it. Devs shouldn't be pressured into providing a Steam option and users shouldn't be pressured into installing Steam if they don't want it or paying prices that are set by Valve on products that Valve played no role in development of.
What will help way more: More high quality Linux native game clients. Also: high quality and performance game dev apis which let serious game shops easily write platform neutral code and ship high quality native Linux clients.