Sometimes products can be time sensitive as far as how long their stay on the market can or will last. This can happen for a ton of reasons. One reason may be that there are so many advances in technology that newer versions or better versions show up constantly.

Sometimes inventors have to get a product to market quickly once invented. That is why you may see on a product that the patent is pending. Why wait for it to happen, rather that company has the confidence that their product is unique and will be approved. This method may not be for everybody though. You would really need to be careful for proceeding this way. If you end up breaking someone else patent you could end up with a huge legal fight on your hands.

So the need to wait or not really depends on the confidence of that person that their patent pending product will be safe on the market before approval. Huge legal battles have ensued do to this type of thing, someone risky selling something without doing their due diligence.