A spindle gouge is not unacceptable. It depends on the grind and how you use it. Typically a bowl gouge has a nose angle of about 55 to 60 degrees. This lets you reach down into a bowl and still rub the bevel. Ideally you should always be doing a bevel rubbing cut for safety, better control and cleaner cuts.
A spindle gouge typically has a nose grind of about 35 to 45 degrees so it will still work for shallow bowls but not so good for steep sided bowls because you can't rub the bevel when going down to the bottom.
A typically from the factory grind spindle gouge will also be really easy to get one of the corners into the wood and you get a catch. This won't happen with a properly ground gouge or a typical bowl gouge.
Some bowl gouges come from the factory with a grind that looks closer to a spindle roughing gouge grind. This is not good for beginners although serious turners do use it. It's just too easy to get a catch.
I use a spindle gouge frequently on bowls for certain cuts. My spindle gouges are ground to 35 degree angle and will cut torn grain better than my bowl gouge so I reach for it as long as it will allow me to rub the bevel for the cut.