The 22nd General Conference on Weights and Measures declared in 2003 that "the symbol for the decimal marker shall be either the point on the line or the comma on the line".

Different countries use different symbols as decimal separators

source: https://en.wikipedia.org/wiki/Decimal_separator

You say: "This also makes the meter conversion inaccurate."
As I can see, there is no inaccuracy for KPLU runway length.
3650 ft = 1113 m , also 3,650 ft = 1,113 m or 3.650 ft = 1.113 m

I don't think that someone could ever imagine of a runway length of three and a half feet!