Why there is a sudden trend in using ASP.NET MVC?

1. Enables the full control over the rendered HTML.

2. Provides clean separation of concerns(SoC).

3. Enables Test Driven Development (TDD).

4. Easy integration with JavaScript frameworks.

5. Following the design of stateless nature of the web.

6. RESTful urls that enables SEO.

7. No ViewState and PostBack events

8. asp.net core which is an open source development platform which suports linux, windows , ios 
9. And core support mvc so the development and hosting cost will be reduce 

 Because of the increacing no of engineers

Its not because of any trend it is because of advantages of mvc over asp.net:

1. ASP.Net request-response pipeline is full of application life cycle events and rpage life cycle events but in mvc those events are not there which makes it lighter.

2. Unit testing was not a feature in asp.net but in mvc u can perform unit testing.

3. MVC provides you better seperation of concern

4. There is no VIEWSTATE in MVC so mvc webpages are lighter.

5. MVC is not a framework actualluy it is a design pattern which ASP.Net MVC applied in its framework which helps you to make test driven development (TDD). 

6. Page load methods and events like postback, crosspostback are not there in MVC so lighter and faster.

 

HOPE this will help you. :)

Enables the full control over the rendered HTML. Provides clean separation of concerns(SoC). Enables Test Driven Development (TDD). Easy integration with JavaScript frameworks. Following the design of stateless nature of the web. RESTful urls that enables SEO. No ViewState and PostBack events

MVC is a design pattern which is devided into 3 layers Model view controller

there is no dependency with view and the controller( which contains besiness logic)

Scalability.

Testabiltiy.

User has full controll over view

Because of following pros available in Asp.Net MVC trending now a days. 

Full control over the behaviour of application.

Extensible and plugable content like we can creae our own html helper method and our own custom view engine.

support all the basics of core Asp.Net like, Authentication, Authorization, Membership and Roles, Session, Caching, Etc.

Due to clear separation of concerns that is Model, view and Controller is totally separate and decoupled from each other maintanance and testing much easier.

URL routing mechanism using which we can built complex URL's whcih is more visible to eyes of search engine.

Because it is very easy to understand, provide good performance, follows separation of concern, provide test driven development environment(TDD), full control over rendered HTML.

1 Clear separation of concerns

2 It has tight control on HTML

3 It is lighter than web form as there is no view state.

4 We can customize every feature of MVC (extensibility).

5 MVC application is unit testable and also works well with UI automation testing tool.

6 It follows natural path. User performs action, and in response the application changes its data model and delivers an updated view to the user.

MVC pattern is very easy to understand and learn. The term MVC can be detailed as -

M (Model) - It holds the data model i.e information.

V (View) - Here we can use advance features of HTML allows to design interactive user interface(UI) which provides better user experience(UX).

C (Controller) - In this part we manipulate the data.

Using this pattern we can provide the clear separation between the  business logic and front end. This is very useful feature in terms of application to be extensible and easy for maintenance.

Because of these certain reasons the most of the developers are going with MVC pattern. 

modern web apps operate primarily on the client side. With WebForms, that's not possible. ASP.NET MVC gives control back to the developer. As a result, modern, thick-client web apps actually work well with ASP.NET MVC.

Plain very simple, it gives you a cleaner separation of model, view, controller and their implementation that help achieve a loosely coupled architecture.
Inversion of Control (IoC) and Dependency injection (DI) are two software design principles that are very well wedded in MVC space.
These design principles are not new in MVC.
They have been around for a long time.
DI is the act of supplying a low level or dependent class via a constructor, method, or property.
Used in conjunction with DI, these dependent classes can be inverted to interfaces or abstract classes that will lead to loosely coupled systems that are highly testable and easy to change.
In IoC, a system’s flow of control is inverted compared to procedural programming.
An example of this is an IoC container, whose purpose is to inject services into client code without having the client code specifying the concrete implementation.
The control in this instance that is being inverted is the act of the client obtaining the service.