I'm sure they could work something out if they ever decided to use them exclusively. D2D is so user friendly and convenient and has all the bells and whistles Steam has and then some.
Not really. D2D encrypts their exes with no hook for addition. This means that there would never be a NVSE(FOSE/OBSE) compatible with a D2D version of the game without a serious change in D2D's policies. Furthermore, D2D only lets you download your games for a limited time. And that's all kinds of inconvenient.
It is one more useless piece of software on my computer.
If you really can't afford the single digit megabytes of HDD space it takes to run the steam client in this day and age, you probably can't play New Vegas anyway. Furthermore, it's a piece of software you can turn off when you're not using it. Compare Securom, TAGES, or Starforce where it's running all the time. Ditto iTunes.
It requires perfect internet connection for single player games which itself requires no connection at all.
Lolwhut. It requires an internet connection to set up your account. Beyond that, you just set it to offline mode and blam. People
say it will have to go online ocassionally, but I've not encountered that myself and can find no evidence of that in Valve's official documentation.
If you have problem with Steam, you will get no support from people who runs it.
I've found Steam's support to be prompt and effective. Have you actually tried getting in touch with them for a legitimate problem? They're not going to help you with "this game crashes" unless you can show how it's Steam's fault, but if there is a problem with Steam, they'll usually get in touch in short order.
You can just hope other users around some forums will be able to help you. It takes away lot of the freedom to use your software. You don't want latest patch because it introduced more bugs than fixes? Bad luck. Once patched, you can do nothing about it.
Solution: Tell steam not to update your game until you're sure you want to update.
But thing that I dislike on Steam the most is that it makes you totally dependant on Steam to use your own software. Software which otherwise does not need Steam at all. No Steam -no fun. I don't want to be dependant on any distributor when using my own software.
The thing I dislike about Windows the most is that it makes you totally dependent on Windows to use your own software. Software which otherwise does not need Windows at all. No Windows - no fun. I don't want to be dependent on any OS publisher when using my own software.
If Bethesda or Obsidian goes bankrupt, I still can play New Vegas which they created. If Steam goes bankrupt I can throw software I bought in to the bin. And please don't start with things like Steam can not go bankrupt or they promised to do this or that if they do. Its nonsense. Companies all around goes bankrupt and nobody will run Steam servers for free.
The main argument against Valve going bankrupt is that, going by every official announcement, Steam is tremendously profitable for Valve. I've heard the phrase "license to print money" thrown about in interviews, in fact. Which makes sense.