In the Age of Computers and Technology why would you want to learn manual Pattern Making?? Well for one thing it's a good skill to be able to do it manually and not rely on computers and software for making a pattern. You get a better fit and you can actually be proud to have done it yourself. A Pattern Maker in the true sense of the term is not a pattern maker if he/she relies on software for making patterns and is unable to produce a pattern without this aide.
It's also an important skill to have for altering patterns purchased from commercial pattern companies and important if you are a dressmaker and designer.
Computer pattern making technology can be a bonus in the manufacturing industry particularly when they produce the same type of design over and over again. It speeds up the process of production saving the companies time and money.
Personally i've not really done any computer pattern making nor does it really interest me. I think that as a Pattern Maker it is important to be able to draft a pattern from scratch using measurements. You have better control over fit and proportions and appreciate the art and skill of pattern making.