Bike bottle interior coatings are not very durable. They're OK for a while if you only drink water and do not scrub the inside with anything abrasive at all. But one good scrubbing with a stiff brush and a few days drinking juice out of that thing, and it will taste bad, probably until you throw it out.
Most people want their bike bottles to be squeezable, so some tradeoffs are made. Everyday bottles can be rigid, so stainless steel (or glass) makes more sense.
Just to be clear i'm talking about the "Purist" bottles made by Specialized the company which use a proprietary coating that seems to work well, not bike bottles in general. See for example [this review](http://www.cyclingnews.com/features/product-review-specializ...). I only recently discovered the bottles so can't give a long term review, the manufacture does recommend against scrubbing them.
Uncoated stainless and glass are great options as well but not practical for some uses.
we buy a lot of these as promo/schwag materials for our business (ridewithgps.com, a bike software website/apps) and they certainly do wear out. I end up rotating mine our after 6 months, and i do not wash them with anything but the soap + water + shake method. the lining wears off and you are left with a plasticky tasting bottle. even new, if you let them sit with water in them for a couple days they'll taste slightly of plastic, so it's not perfect.
much better than any others we have tried though, so worth it.
Most people want their bike bottles to be squeezable, so some tradeoffs are made. Everyday bottles can be rigid, so stainless steel (or glass) makes more sense.