A workaround you can do is, before launching steam disconnect from the internet, then launch steam, when it launches it will say no connection and give an option to launch in offline mode, once offline mode is launched you can turn your internet back on. Just keep in mind steam also has to refresh your games every once and awhile as well so you have to go online at /some/ point or it won't let you play the game offline anymore. Steam is super annoying in that matter.