yes, the kernel generic should contains only a minimal set of drivers, the only needed to load an initrd image, so that kernel may be smaller as possible.
However that kernel contains a number of driver sufficient to boot _all_ my systems. My initrd contains the ONLY filesystems driver, that I must regenerate at every kernel update.
Also is impossibile to choice the kernel generic at install time.
This does not encourage newbie users to use that kernel.

The idea (the request) is to add builtin, in the distributed kernel generic, the drivers for the most used filesystem (ext3/4, reiser).

I don't think that a similar kernel will be too big nor that a similar kernel lost performance, and I think that it save many time in installing/upgrading process, and it save many user from many kernel panic (and I know how to repair to a kernel panic, but for some user the solution is to reinstall)

I always choose the generic kernel at install time. Various READMEs in the top level directory of Slackware DVD mentioned installing an initrd during installation. If the bee is too new then it should choose the huge kernel during package selection.

No. Therefore, you have the choice of the huge kernels during installation (on package selection).