^^ Right on.
About half of my post I lost earlier was about this. What is a drug? It's a chemical that binds to receptors in your nervous system and produces alterations in the way your mind-body system is functioning, whether with mental effects or just something physical, or even some subtle tweak of your biochemical makeup you wouldn't even notice. By this definition, emotions are "just" drug experiences since they're the result of endogenous neurotransmitter firing. Thought itself could be considered a drug experience, since the methods by which neurons work to communicate uses chemicals to facilitate.
So how does it make sense to differentiate between your body producing substances to alter the way you experience life, and introducing a foreign substance into your body purposefully to trigger an altered state? How is it different from meditation, where one purposefully enters an altered state of perception through willpower. As long as you're responsible with what you put into your body, it's perfectly okay to do so if you're not hurting anyone else.
So to actually answer your question, it really totally depends on the person and how they take the experience. A lot of people are looking for colors and visuals and laughter and they take it in situations that are conducive to social activity and generally centered around having a lot of crazy fun. For many of these people, they are just other drugs, in the sense that they see them as fun, powerful, but basically just a recreational experience they haven't gotten anything meaningful or applicable from.
Other people might take a psychedelic and end up having a powerful spiritual experience or come to some really important conclusions or realizations about their lives. So for these people, psychedelics, while being technically defined as "drugs", are not thought of in the same way as non-psychedelic drugs. They are a special class that produces a state which is amazing to experience and enlightening and they tend to be thought of more as "medicine" or "sacraments" rather than "drugs".
Or, if you look at it another way, any chemical is "just a drug". The drug itself doesn't have magical properties. The drug locks into certain receptor sites in our bodies and gets metabolized and as these things happen, an experience begins to happen. But the drug itself isn't something unique from other kinds of drugs, but the experience you had as a result (you could also have a powerful experience while sober, particularly if something really intense happens or if you're at a place that inspires strong feelings and experiences such as the Grand Canyon.
Like with all things in like, it's all about how you look at it.
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