Having built a small pond with a liner, there are drawbacks:
1. Puncturing the liner. Drop a rock, step in a bad spot with something sharp on your shoe, drag a boat, get your hook stuck... there are numerous ways to get a leak. Will any one of these be enough to drain a large pond? Probably not, but get enough of them and perhaps...
2. In cold climates critters that need to hibernate in the mud will find none on the sides unless the liner is buried under more soil.
3. Very tough to install all of that heavy material in one contiguous non-leaking piece. You really need someone who knows what they are doing to get it right. Probably very region dependent to find that expertise.
4. Planting is impossible unless you set up ledges to hold pots of plants. In a 1 acre pond this is probably impractical. With a natural bottom, plants can naturally spread. But on a rubber bottom, nothing. Again the liner would need to be buried.
5. The natural look is compromised and will take some work to hide the liner edge.
6. Slippery as all heck. Plan on doing a lot of swimming while you are working on it.

However they are perfect if you have no other means for holding water. Example: My garden pond required one or it would have run dry in hours. It looked good (until I tore out stuff last summer), but took a lot of work. Perhaps will get it up to 20x30 this summer from 8x10, but low priority now with the much larger pond to deal with. Sort of an eyesore right now.