Th D Thangneilar Chiru

Good question. 

Just imagine drinking tea without sugar.( what will be the taste like) 

Music or a band without guitar/bass guitar.. Just drum and piano or other instruments will the same as above statement.. Guitar itself is giving the band more unique sound and also make a complete musical band. Guitar has a big role in musicmusic. It exaggerate the bands and provide more extra sounds.. Playing solos adds more uniqueness of music and also highlighted the bands skills and ability.

Its quite an interesting question.

Of course there's virtual guitar available online

You can learn from it. The notes)scale or chords but it will be like playing computer/mobile games.

Learning musical instruments needs physical efforts and practice. Of course can learned musical theories online but not practical without instruments..

Learning guitar without instruments will be only theoretical. Eyes/ ears doesn't play guitar but our hands and fingers does. 

""We can't be like sachin tendulkar by just watching his cricket match""

There's no particular reason which is better or which is worst because they are in same category of( plugged stringed musical instruments) its just a matter of choice, usually acoustic are mainly used as play and sing along ( it can still do the same as classical) and usually classical are of fingers playing melody along with bass line in one instruments ( two in one).

It's not only about chennai, its just a matter of budget. Some branded instruments(4000-6000) produced better sound with lower price, some india products with same amount doesn't have the quality sounding. Visiting the store is best option and good quality sounding guitar can be hard and recognize easily with smooth clean and more melodic tone.