We've all taken classes that were perhaps too focused on the physical and not enough on the breath or the vrittis (whirling a of the mind).
But I think there can be a balance with this. Perhaps you want to do the occasional hard-core hot yoga for a physical challenge or to burn off last nights pizza or ice cream? Why not if we take pleasure in it:)? Additionally, there are hot yoga teachers that do inject the yogic teachings into the classes. Trying to merge the main stream demand for a "good work out" and a spiritual demand for stillness.
Balance, balance, balance:)
For me as long as I frequently attend classes that help me draw inward instead; the classes that remind me over and over that the breath is all that matters - I keep my perspective.
Classes like I took today where I hardly had a thought that went beyond the edge of my mat! It was son pure and lovely.
Then I feel like I can stay balanced within - the physical, mental, spiritual - maybe not perfectly all at the same time, but still moving forward with that intention.
Breath, Bandhas, Drishti, Yamas, Niyamas...if we don't have those in our practice, Is it yoga?