bug_of_war said:
They rely on the Source engine which is arguably quite out-dated, they frequently re-use audio files and textures,
Re-using and constantly updating the source engine was a brilliant move on their part. It let them make more games faster, and with an engine that has always done what they needed and runs on the majority of computers. I'm sure they'll come out with a new engine or complete overhaul of Source when they feel the time is right (probably in the next couple of years), but they've been much smarter about managing their technology than a lot of other companies. As for re-using audio files and textures, I have to wonder why this matters? Why make something from scratch every time you need a rock when you've already made a perfectly good rock in the same engine for a previous game? Wasted time and money unnecessarily duplicating effort just seems silly to me.
in terms of focusing on what their audience wants they seem to ignore their fans (when's the last time you heard anything bout Half Life 3? Or Half Life 2: Episode 3?),
The funny thing about audiences is that they're incredibly short sighted and you're probably better off not listening to 90% of them 90% of the time. If the fans had their way, we'd have Episode 3 instead of L4D, Portal 2, etc. And it wouldn't be a big change over Episode 2 and the original Half-Life 2. Basically, we'd be missing some great games in favour of the stagnation of the HL series in the same way COD and other series have repeatedly stagnated with quick release schedules. It's ironic to say that because they used the same engine and haven't made the sequel their fans constantly ask for they've stagnated when the truth is the exact opposite happened.
they spend more time making hats and items for TF2 (still a popular game, but it is an old game),
I don't think they even make the items anymore with the workshop being a thing that exists. Even if they did, they've released at least a game a year since TF2 game out making this statement objectively wrong.
and whilst they've made unique games with new/interesting mechanics, none of them have been explored much further (Portal 2 isn't my game, but it's unique gameplay makes me curious as to why they aren't making new maps/a new game based on it's gameplay mechanics).
When I see this argument, it really sounds to me like "Valve hasn't released sequel after sequel to the same game using the same basic mechanics instead of making new and interesting titles that actually push boundaries." It really seems like you're asking them to go the COD route instead of innovating and I have to wonder if you actually know what stagnation means at this point.
Valve hasn't stagnated. In fact, they're probably the least stagnant company in the business right now. They are always willing and able to use the copious amounts of money they have to simply go off and do whatever they want whenever the mood strikes them rather than chasing COD levels of sales by making COD every year.