A young artist's work looks different to that made by someone older. I consider this maturity a neutral quality; not better or worse. In many ways mature work is superior; someone who has honed their craft and observed human nature over many years creates with a deep understanding of what they're doing, knowing how to apply conventions perfectly and when to break them to achieve the exact effect they're aiming for - not just for the sake of it. But youthful work has its own value, the energy of exuberant joyful ambition and experimentation, discovering ideas for the first time and getting excited about them in a way that a jaded older person can't anymore, still believing they can change the world. Neil Stephenson's Snow Crash isn't clearly 'better' or 'worse' than Anathem, but it's much more energetic. Split Enz's Time and Tide isn't 'better' than Mental Notes - although it is easier to listen to.
As an artist I don't think maturity is an important consideration; it's not a decision for a piece to be more or less mature, the type of thing you make naturally changes as you age. But as an audience, it's valuable to recognise the merits of both youth and maturity. And as an industry, it's important to support both - for if young artists are not supported, there will be a dearth of mature ones in years to come.
Videogames are a mature medium, and over-focused on maturity. Young men (it is mostly men) sacrifice their careers for the visions of old men (again, mostly men), rather than creating things of their own. (The old men usually design games for young men, leading other old men to complain that games are immature; they're not: they're using their mature powers of expression to make things for a younger audience. This is not a problem in itself, it's perfectly possible to make things for an audience you are not yourself part of, as long as you don't condescend.)
The days of the arcade, where every second game was new and strange and different, are long past. (The rest were clones, but never mind those.) That cacophony of ideas has been replaced by fixed genres, mostly the fully consolidated FPSRPG - a powerfully mature setting for a certain kind of interaction and storytelling, but a very limited thing to be the main thrust of our medium.
Fortunately "indie" is a thing - although, most of the reason it's recognised as such is because of old men quitting large studios to strike out on their own, and approaching it with a mature attitude. The most highly praised "indies" are mature developers producing polished work on a strong foundation. That's okay, it's okay to respect them, to appreciate their work, to raise them up; they do good things. But it's the wild experimentation of youth that created that foundation they're building on. The genres that seem inevitable today were once new ideas indistinguishable from the froth of other exciting ideas around them, and new things that don't fit into the genres are still out there to find if we look (and it's not hard to find, I see a lot of low-hanging fruit out there).
There's the money issue; it takes time to make ambitious games and so often you'll need money up front to live on while developing something. Publishers have been derided for their tendency towards caution, choosing only to make reliable investments in mature developers working in mature genres, avoiding youthful experimentation. But crowdfunding has changed little; old men easily summon up silly money at the drop of a hat to make more of the same - even though they have enough in the bank already - while deserving young artists struggle to get by.
I feel (and this is an awkward and probably controversial statement that I'm not entirely certain about) that in general players of videogames lack appreciation for young work. Mature work is appreciated, and that's good. But the value of outsider art made by someone with no knowledge of conventions (Darius Kazemi has written about "outsider games"), or of ambitious but flawed work by brilliant young artists reaching beyond their abilities, I feel that these are not understood. I feel like this is not the case in other media, that energetic amateur music is appreciated (Brendan Caldwell made an analogy between games and punk rock in a series at RockPaperShotgun), that primitivism and abstract expressionism brought a good understanding of this value to the world of visual art, etcetera.
And this is a problem; we have a community that fails to appreciate the youthful work that's being done, that fails to fund young artists, and that pressures young artists into aping mature work rather than honestly expressing themselves, ultimately limiting the depth and variety of what gets made.