I love you. Years ago an Answerbagger(not on Answermug...was briefly) said saying I Love You too often makes it meaningless. Agree/dis/why?

It can come across as insincere. However, when said with conviction, it always has meaning. I tell my better half that several times a day - truth cannot be too often repeated.

Maybe to that person it did.  It depends on the person saying it and how effective his/her words actually are. 

Probably breeds just knee-jerk habit and, therefore, meaningless.   But some people can genuinely mean it and, therefore,   pull it off nicely.