Is it bad?  Well, it is damaging the fingerboard.  Eventually that will make the instrument harder to play properly, and need either repair or getting a new instrument.  Most people tend to want to avoid that.  Should you stop doing it?  I suppose it depends on how often you want to replace the instrument or have it repaired.  

Is it generally considered an acceptable type of vibrato on violin?  Not really.  Violin vibrato works more by rolling the finger along the length of the string than bending it sideways.  So far as I know, teachers and etc wouldn't be recommending bending the string. 

Is scratching on the fingerboard common?  Well, I don't know how long you've been playing on that particular violin, but scratches like that aren't something I've seen in the 3 yrs I've been playing.  Wear does happen on the fingerboard, they don't last forever. But that looks like it is digging it up pretty good. 

There are some guitar vibrato techniques that are quite close to how it is usually done on violin, but that is most often used by classical guitar players for a more subtle vibrato than bending the string.

Bending the string isn't really necessary on violin.  If you want a note to bend up in pitch, you can just slide your finger up and get that sound, since you don't have frets to cope with.

I would say there is some similarity between guitar and violin vibrato in the need to relax the hand, wist and sometimes the elbow enough to allow the movement to be be easy and fluid.  But how the effect is produced and what is happening to the string when you do it is different.