ASP.NET as a platform runs fine and is well supported. So does SQL Server. (SQL Server is loads better than MySQL).
Are they using SQL Server? I can't tell from just a cancel notice and a http header. Wouldn't surprise me if they are. They'd have to have a reason to not go with a full MS stack.
Anyway, SQL Server has never bitten my ass, so I've no gripes about it. For doing standard corporate CRUD apps that don't require much in the way of performance and do require ACID compliance it is a much better choice then MySQL.
I really doubt ASP.NET is the cause of Gleemax's failures.
I doubt it's the only cause...
I'm not saying this to insult anybody, but I really do believe that if Wizards had gone with LAMP and the typical programmers and designers that usually work with such they would have had better results.
(Sharepoint is somewhat of a beast though and I wouldn't recommend it for public high-traffic sites.)
I don't follow Microsoft in the server world(obviously) so Sharepoint is new to me. Reading a bit about it I can only say WTF were they thinking?
Anyway, Plane Sailing is correct. Do not fall for the trap of "Microsoft Sucks, Open Source Rules". Anybody who is prejudiced against Microsoft should take a look at the problems companies like Twitter and other Web 2.0 companies are having using a Framework like Ruby on Rails, or the problems MySQL has with certain tasks. There is no perfect platform.
It's not really a Microsoft vs everybody thing.
The more your app deviates from the framework defaults, the more trouble you're going to have with something like Rails. This is almost the same problem I think Gleemax was having. I'm not making an OSS advocacy argument. I'm arguing that they should have used better suited tools.
Sam
PS, I'll look up the Twitter/Rails thing. I could use a good laugh.
[Edit]
Ok, I've read a bit on the Twitter thing. Scaling issues are not what I was expecting. If they had expected that kind of traffic and load, Ruby on Whales was not a good choice for anything past prototyping.
[Edit2]
Though it has nothing to do with the Gleemax crap, the steps that web apps like Twitter, YouTube & Flickr took to scale are fascinating.