Sorry folks, but it sure is !
The Lydian Dominant scale represents in fact a mode of yet an other scale, the ascending form of the classical Melodic minor scale from Classical Western music.

Audio 11.6

So the Lydian Dominant scale is a mode formed on the 4th note of the Melodic minor scale.

This Melodic minor scale and several of its modes are extensively used in Modern Jazz improvisation. For more on this see my Scales Book (Chapter.8) or the Jazz Theory Course on CD-ROM.

What about the Blues scale ?
Although the Blues scale also contains a #4 (or b5) it has not the typical bright sound. On the contrary, it sounds very 'syrupy'.

Why is that so ? Simple.
In the Blues scale the #4 is added to the scale, the regular (perfect) 4th note stays in the scale.

The Lydian sound is produced by replacing the 4th note by the #4 al together (so the regular 4th is no longer in the scale).
This may seem a small point, but it makes a huge difference to the sound ('tonality') of the scale.