[Example] Is half life Non Steam legal

Based on above , Is half life non steam legal .
Since Steam doesn't support their server for non steam users ,
will this make non steam ILLEGAL?

in my opinion ( IMO ) , it is illegal as Steam Company will loose money on that .

it is legal .

Because there exist WON and STEAM .

When half life came out . all people can play together . And when steam exists , half life started to use steam which all people who is steam can only play their master server . Doesnt means that they cannot play other servers . This means they cannot play under the provider of steam ( for non steam ).

But still only CZ ( Counter strike condition zero ) have won . Counter strike 1.6 USUALY dont have WON.