Let me guess, you've never actually used the A7 or the Zeiss 35mm, have you? I have the A7 with the Zeiss 35mm f/2.8 and it is sharp corner to corner. It also measures objectively higher in sharpness than the sigma 35mm f/1.4 ART (dxomark). Not to mention it's also very light, compact, and weather sealed.
I've used both the Canon and Zeiss 24-70mm f/4 lenses, and the Canon doesn't do anything close to "toast" the Zeiss. Once again, objective test put the Zeiss lens sharper than the Canon, too.erictron wrote: ↑The quality is decent. The 24-70 f/4l has far better aperture (f/4 thoughout vs f/5.6). If you stepped up the Canon 24-70 it would toast the sony in terms of image quality. Lets not even talk about the 24-105 f/4L IS. Lower aperture, image stabilization, better range, and it's damn sharp.
In conclusion, nearly every kit lens included in a full frame package is better than this. The only thing I can think of to compare this to is the 18-55 f/4-5.6 that comes with Rebel. Sure, the Sony is sharper. But that's all it's got.
You seem to love crapping all over the Zeiss lenses with no concept of how they actually perform. Zeiss has a long history strong performance and a solid reputation among photographers, and, lately has produced some of the sharpest lenses.