It started with the grandfather clock. Everyone's clock pendulum needed to be the same length to have the same length of a second. So a meter also happens to (approximately, this was before we could easily be precise to several decimal places) be the length of pendulum that cycles at 0.5 hz (each swing back and fourth is a second) in 9.8 m/s^2 gravity.
I think there were multiple competing suggestions at the time, the grandfather clock was one while the standard ended up being the French proposed one that you mention
Ah yes, you're right. Another nice coincidence that a seconds pendulum is less than 1% away from 1/10 millionth the distance between the equator and poles.
