He sucks
A very close minded comment; Construct is certainly not male.
It is slow and different from others
If you can find a faster game creation program I'll give you a flying salmon.
It uses DirectX, or anything Linux or Mac, unlike other open-source programs.
Where is it said that all open-source programs cannot use DirectX, or even that a majority don't??
Use SDL or Allegro sluggish than the game
What?
If you want to make a point about things which could improve Construct, don't pick arguments in the areas that categorically cannot be true. While more programmers and multi-platform capabilities would be nice, the majority of the gaming market use Windows. The one thing which surely cannot be in any doubt for anyone in the world who has used Construct is that it is slow. It's highly optimised and written for speed.