از مقالهء ویکیپدیا چند مورد از مسائل Mono رو درآوردم:
Windows Forms 2.0 is also supported, but not actively developed, and as such its support on Mono is incomplete.[31]
Mono's aim is to achieve full support for the features in .NET 4.0 except WPF (which the Mono team do not plan to support due to the amount of work it would need),[31] Entity Framework and WF, limited WCF.
Canonical Chief technology officer also said about Mono: "With regard to Mono, I think it is a valuable piece of free software for us to have. However, there are risks involved in choosing the .NET platform to develop free software, because it is under the ultimate control of Microsoft. Microsoft could take advantage of this to attack free software in various ways. This would be a logical act of self-preservation, and consistent with their previous actions and statements of intent."
همونطور که میبینید از نظر فنی و نیز از نظر قانونی/سیاسی دات نت با مشکلاتی مواجه هست که در اون حد کوچک نیستن که بشه براحتی نادیده گرفتشون.