Thing about python is its not professional
You're joking right?? Do you know how many professional projects from Google, Soya, Blender, Panda3D use Python?
people will refuse to play a game that makes you DL python (assuming it requires that installed) or uses it.
Why would a person care that Python is used in a game? and for the record end users do NOT have to download Python for it to work with Construct. Only developers need to do that. If you are concerned about the user seeing the Python DLL, just package your game in an installer and the end user wouldn't know if Python, C, C#, etc was used without browsing through the install directory.
Happens all the time...
There are obviously pros and cons to using Python. Certainly, if you want blazing performance for certain sections you need to write those portions in something other than Python or accelerate with Psycho. In addition, the Python integration with Construct could use quite a bit of polish.
All that being said, in 99% of the users here what language a game is written in won't matter assuming it gets the job done. You can write good and crappy games in any language.