With a very large outboardmotor, for example, the boat may be imbalanced by having that weight far astern and may "squat" in the water and not sail as well.
If you are looking for a large daysailer or a small cruising sailboat, you may be choosing between sailboats that have an inboard engine and those having an outboardmotor.
We found ourselves on the beach, surrounded by untidy-looking crates and bundles, together with the small boat and its outboardmotor which would be our only link with civilization.