This rule change will draw away weaker/lesser playered factions from pvp more
Before that change people thought "hey its not that bad, we can try our chance agains gank force and log when they logged off."
Now its "OH NO A GANK RUN RUUUUUUUN"
Its bad for overall health and interaction quality of disco. Now a new age born. Age if more QQ, more drama, more bullcrappery, crap encounters, gankers ruling sirius and others watching in their burnt ships!
You will have certain players/factions intentionally logging large forces to deny the game to weaker ones completely. In the end playerbase will diminish even more.
And @Jack_Henderson explained transport situation well. Its only loss for transport now.