That's why uploaders should mention a matching release - and downloaders should use that one.
The 'problem' with resyncing HDTV version subs for WEB-DL video and vice versa, is that it is not just a shift forward or backwards and/or changing frame rate. The resyncing should be done for every piece in between every ad-block. Still, with some experience this is not too much work anyway.
However, getting a DVD version subtitle matching a BluRay video, this shouldn't be too hard. Maybe only a shift, maybe only changing the frame rate, worst case scenario is both, or you can/have to do a socalled 'point sync'. This is having two matching points (at the start and at the end of the movie) and have all times in between adjusted accordingly. With subtitle software this can be done in a few minutes.
I guess I will need to learn how to create subs and start contributing to the community.
Yeah, why not. If you want that subtitle, most probably others want it too.
Subtitle Edit is free, open source, handy and brilliant.