Yes, put it on other distribution platforms. Don't put all your eggs in only one basket
.
I would say, good luck to reach GOG, they are much harder to get in that greenlight; but worth the try (if I remember well, Prison Architect get rejected at first try - for a game that sold more that 1M copies
-). Some of recent AAA titles sold as much copy on GOG then on steam.
I don't remember the exact stats of the guy who made regency solitaire, but he had a solid amount of sells outside steam. I think it was also him who advise was even not to start on steam, but on smaller platform like indigamestand, where you can get better feedback to polish your game before putting it on steam. The false believe that to be a serious indie you have to be on steam, is more the result of valve successful marketing of their platform (on players & devs) then what the best for you in reality.
piracy, is a half-false problem. Cite any successful indie/AAA game that didn't get pirated^^. Being afraid of piracy and missing opportunities because of that cost you as much or even more then piracy itself! (and from some story I read, it seams today what worse is the chargebacks on credit card and stole of key resell through stolen card)
first, because a pirated copy = a sell missed is just an hypothesis, not the reality (I truely believe you loose some sell, but thinking that every download is a sell missed, is just silly - and seriously, what do you want max your sell, or players being happy about their buy and build a long term confidence in the audience ?)
don't remember who said something like this: You should hope to get pirated. Bad games don't survive on P2P, who want to take the risk of sharing a pirated version of a bad game ! (personnally I think it's more the ratio of the quality of the games/overprice/hype - that could also mean, that if you don't get pirated, you don't charge the max, so perhaps you don't optimize your revenue - but in some way, piracy is some form of advertisement, that not cost much more then PR)