Point taken.
IMHO, our ancestors used the kris as a tool than a ceremonial trinket. If you may, in order to differentiate the two, I'll use the word
kalis to mean the filipino design and
kris to mean the malaysian design.
The kris (or kris dagger since the size was more of a dagger's) was often used for ceremonial purposes (such as execution) and was often times carried (or worn) to denote prestige. Its wavy design and thinness made the kris effective only as a stabbing weapon. Going blade to blade with another weapon, IMHO, would break it. I recall my teacher calling it a "magic wand" of sorts.
The kalis is made to be heavier, thicker and longer. Its design made it possible for a stabbing, hacking and slashing movements. The keris was used more of as a weapon (though it also was used as a sign of prestige). And yes, i agree with what you said about the kalis and its straight design. More practical than the original kris design, yes?
It's no surprise if there were influences in our blade design. After all, as you said, iisang lahi lang tayo.
Hell, if you ask me, if i were to choose between the kalis and the kris in a fight, i'll pick the kalis any day.
Oh and personally, i think the Kampilan should be the national sword (and should truly be the Ancient Filipino Weapon, don't you think?haha). Pinas lang ata ang may ganun na design.