C# doesn't really have many weaknesses aside from that there isn't official Microsoft support for .NET on platforms other than Windows. I'd assume that you are primarily referring to ASP.NET about bad points, not my beloved C#.
I've found that most of the time these days, I've been using C#/ASP.NET as my primary freelance web development platform. Not really because I think its the best (I usually use PHP or occasionally RoR for personal projects), but there's just so many spectacular .NET commercial libraries that save a ton of development time and money. Plus, it doesn't hurt that C# is a joy to develop in (the only language I find to be more fun is Ruby, which is limited in its usefulness).f2富二代官网入口