I looked at your site. See that scroll bar on your menu (left column). That WAS a problem for all of us back in the 20th century because of framesets. You might be happy with that, but I never was and for once in my life the vast majority of coders weren't, so it was changed along with adding images to the web. You may like the 50's look of your homepage; it maybe what you were trying to achieve. Surprised you don't have colored or moving <hr> separators.
All the typing saved by using framesets is lost when <noframes> content has to be written. I have never heard of security problems with framesets, what I did hear was google has a hard time with them and if you want a higher rating don't use em, but I don't know.
Use em if you want. I just believe they will be gone soon, not one major web site uses them, lots better ways to do things.