You can't help if you can giving excused for Gigantic not having a big player base. The problem is not Windows 10, windows 10 was free and it is still free for 7 and 8 users, you could even get it free without having a legal license. I mean, more than 50% of steam users are using Windows 10, many use other services like Origin and Battle.net, in game that don't need steam at all, but it seems it is a problem with Gigantic being on an alternative service?

I mean the reason this game has more players is thanks to the crossplatform between xbox and PC, which needs win10 and xbox services. so the problem is not technically it being on Win10 store (which is installed by default so no excuses)

The problem is Motiga not promoting the game, and then they expect it people to do that job for them.

The problem also is many people quit this game because it gets boring after few days, or it is hard to win for new players because of smurfs and all, because Motiga has listened to the wrong feedback and after leaderboards came to life, smurfs are not helping in the progress of the game where you can't even play as a new player because the other team has 3 smurfs and they win in 5 minutes.

People keep quitting the game so it rarely ends 5v5 for new players (watching new player streams). it is pretty tough there.

Now the problem is also with high level players where Matchmaking seems to give us really new people to "average" MMR. You might say people need to wait for competitive mode, and just have fun. but how can you have fun when the matches aren't balanced because of MMR system and leaderboards that suck? it is Motiga's fault all they are doing and they have not done in this game, they listen to the wrong feedback and when you think you can win a match, someone quits after dying once.
Last time it happened to me, we were winning and someone quitted, again, the same person quitted weeks ago stayed AFK the whole match and right before clash he quitted... like why are this people allow to play if they quit matches all the time? and that's another mistake by Motiga, give penalties to the people who wants to play like 40s bug, and never give enough to the ones who really quit matches.
What is wrong with dodging matches? all this Matchmaking system is so bad implemented that I can't even dodge a match when I see players that are not good or always quit, because I would get a penalty, so that's not fair either.

All goes to Motiga's shoulders, the problem is not being on Windows 10, the problem is they don't promoting it enough, having a really buggy game and don't fix many problems about the Gigantic's gameplay that ruin the experience.

So people, new or old, end up uninstalling the game because they see there is no point in playing such a frustrating game, not being of losing, but because it is impossible to have a nice match, balanced, maybe with friends (because of queue time), and at least people around your level, who will not feed like crazy. apparently that doesn't exist in Gigantic.

A game can't grow if it is like this, if they put the excuse of "it is beta". when it hasn't changed much since closed beta and that was a year ago.