it's easier to use existing code then reinvent the wheel and code base for C++ is huge compared to Pascal when it comes to gamedev.
Second -when looking for work in the industry Pascal is not of high demand - anyone knows of a major company using it for writing games?
For those two reasons I say that it's not optimal decision to use what we use I don't say it's a bad decision, just not best if someone wants to be a 'pro'.