Why can we not use water instead of blank control solution in enzyme catalysis with Peroxidase experiment?
It is because the water blank absorbs so much light that the usable scale is compressed, thus, causing a poor accuracy.


For water, the absorption coefficients $\alpha\ [\mathrm{m^{-1}}]$ at $\lambda$ = 680, 580, 535, 480 and 380 nm are 0.47, 0.09, 0.045, 0.013 and 0.011.

(Source: R. M. Pope, E. S. Fry, Applied Optics, 1997, 36, 8710-8723)

That is not a lot.

On the other hand, you never know about impurities in your buffers or other components (apart from your probe). 

Therefore, you usually do not measure against "just the solvent", but against the solution of "everything except the probe" to record the complete background.