Do all Buddhists abstain from alcohol?

All practicing Buddhists abstain from alcohol. It is disrespectful to the Buddha for a restaurant to display a statue of the Buddha in such a setting, but sadly that type of thing is all too common.

In Buddhism, drinking alcohols itself is not considered to be a sinful action. However, when you get drunk and lose control of your mind, you go around and hurt yourself and/or someone else. That would be a bad karma to do so, which is why drinking alcohol or taking drugs are actions that should be abstained.

However, Buddhists who are elders or those who enforce rules in their own community may actively prohibit their fellows to not take alcohols at all at their discretion.

It's disrespectful to use buddha statues for decorative purposes in bars or anywhere else. It creates bad Karma for the person who does it. Yes, the 5th precept covers both drugs and alcohol consumption for non medicinal purposes.

I think it's an interesting question and certainly different people have different views. Royokan the Japanese Zen poet wrote about getting drunk amongst his writings about being a dedicated zen practitioner

"I send one of the children to buy some country wine/ And after I'm drunk, toss off a few lines of calligraphy."

(referenced from the same wiki article)

I don't think that anyone would doubt Ryokan's commitment with or without a glass of sake.

Rather than the "fifth precept", I find it stranger that it seems to transgress "right livelihood".

Sankha's answer notwithstanding, I like to (I am happy to) see a statue of the Buddha if I walk into a restaurant.

A few of the "10 bulls" commentaries imply that Buddhism and alcohol can, perhaps they hope, co-exist. For example,

X
Entering the City with Bliss-Bestowing Hands

His humble cottage door is closed, and the wisest knows him not. No glimpses of his inner life are to be caught; for he goes on his own way without following the steps of the ancient sages. Carrying a gourd he goes out into the market; leaning against a stick he comes home. He is found in company with wine-bibbers and butchers; he and they are all converted into Buddhas.

Barechested and barefooted, he comes out into the marketplace; 
Daubed with mud and ashes, how broadly he smiles! 
There is no need for the miraculous power of the gods, 
For he touches, and lo! the dead trees come into full bloom.

Some versions of that show him with a "gourd". When I first saw that I thought it meant a "wine container", because this is how it was published in Paul Reps' book:

Comment: Inside my gate, a thousand sages do not know me. The beauty of my garden is invisible. Why should one search for the footprints of the patriarchs? I go to the market place with my wine bottle and return home with my staff. I visit the wine shop and the market, and everyone I look upon becomes enlightened.

But the footnote in this reference says that in the sentence, " Carrying a gourd[2] he goes out into the market, leaning against a staff[3] he comes home", the gourd is a "Symbol of emptiness (sunyata)".

That's a row of Chinese Buddha's and Bodhisattva's, so this appears to be a Chinese restaurant.

Monastics have always been held to the strictest standards-- there was a very concrete, this-worldly consequence for breaking the precepts-- you would be kicked out of the sangha (or more likely punished by some other means).

Where the rules are less straight forward is for lay followers. Upasaka are encouraged to follow the five precepts, but if they can't then they are urged to follow just 4, if not, then 3, and so on. And if they can't follow any precepts, lay followers are urged to at least take refuge in the Buddha, the Dharma and the Sangha. I take this to mean that ethics in Buddhism is a practice where you start where you are and over time you get better, as opposed to ascribing to all the rules and following them rigorously on day one.

As for if this is offensive, depends on where you are. I would guess this is offensive in Sri Lanka and Thailand. As a US convert, it doesn't bother me at all, this restaurant didn't do this with the intention of offending old ladies in Sri Lanka.

But in the US, I give them credit for actually being aware of customs regarding home shrines-- it is not uncommon to see suggestions that the Buddhas and Bodhisattvas be put in the highest place in the house. This makes me think the person who put them there is a believer and not just decorating with curios.

All Theravada Buddhists abstain from Alcohol. This is well explained in "THE FIVE PRECEPTS" which is a very good read on the 5 precepts.

The fifth precept reads: Surā-meraya-majja-pamāda-ṭṭhānā veramaṇī sikkhāpadaṃ samādiyāmi, “I undertake the training rule to abstain from fermented and distilled intoxicants which are the basis for heedlessness.” The word meraya means fermented liquors, sura liquors which have been distilled to increase their strength and flavor. The world majja, meaning an intoxicant, can be related to the rest of the passage either as qualified by sura,meraya or as additional to them. In the former case the whole phrase means fermented and distilled liquors which are intoxicants, in the latter it means fermented and distilled liquors and other intoxicants. If this second reading is adopted the precept would explicitly include intoxicating drugs used non-medicinally, such as the opiates, hemp, and psychedelics. But even on the first reading the precept implicitly proscribes these drugs by way of its guiding purpose, which is to prevent heedlessness caused by the taking of intoxicating substances.

This is oftentimes an intensely debated precept.

Yes, the fifth precept is understood differently by different people, i.e., sometimes people interpret it to mean abstaining from all drugs or all intoxicants. It usually always includes abstaining from intoxication and heedlessness from alcoholic drink though; some people may interpret this as allowing them to drink in moderation.

If I had to guess, the person that was responsible for putting those Buddha statues in that bar thought they were cool and has no idea about the precepts.