Can I make a game without a game engine and use only C++ and libraries like SDL2?

I'm sure you can! They said any game engine or software .  Just know you're less likely to get someone to continue after you because most people use game engines.

if you ask any seasoned dev...well let's just say we have a grudging respect for people that don't use game engines

I agree, I don't know how many people out of 397 would know much about C++, or want to use it. I highly respect C++, as it has been used for...forever. 

i agree too, not many people will be willing to use c++ and SDL2 for this, so you might not get any people continuing it