Of course it is helpful to use a keyword generation tool to help you complete your keyword list. Not only will it help you round out your list with keywords and phrases you may not have thought of, but it also gives you ideas on what others may be searching around your topic.
Take the keyword “copywriting” as an example. A copywriter might think of obvious keywords to optimize for, like “copywriter” and “copywriting” but may not think to optimize for “copy writer” and “copy writing”. Believe it or not, people often search for products and services by using common misspellings and because they are misspelled so often, the search engines recognize them as actual searches. This requires creativity and know-how on your part.
So, for these reasons and more, keyword generators can be and are very useful tools. However, they are not meant to do your SEO work for you. In other words, they are there for guidance and word generation. They are not meant to serve as keyword managers nor do they have the ability to create entire SEO campaigns for your business.
Only you can create the best, most effective list of keywords for your website and it should be completely unique. Why? Because your business, although it may be one of many in its field, is one of a kind. Therefore, you should optimize it as such. After all, that is what sets you apart and will continue to set you apart as you gain new customers from well planned and effectively executed keyword optimization.