On 13 July 2017 at 03:04, Gregory Maxwell via bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org> wrote:

Can you explain why you wish to do this? It should have absolutely no
adverse impact on you-- if you don't use segwit, you don't use it-- it
may be the case that there is some confusion about the implications
that I could clear up for you... or suggest alternatives that might
achieve your goals.

I believe that a good reason not to wish your node to be segwit compliant is to avoid having to deal with the extra bandwidth that segwit could require. Running a 0.14.2 node means being ok with >1MB blocks, in case segwit is activated and widely used. Users not interested in segwit transactions may prefer to keep the cost of their node lower.