This change doesn't bother me as much as it seems to with some people.
Lately, I have tended not to rate any shows unless I give it a 5-start because I thought it was good.
"Was that documentary I just watched worth a 4-star, or maybe a 3-star because the middle part was boring?" I usually don't put in that level of mental effort to try to fairly rate something.
This way, I won't have any compunctions thumbing-down a lot of the crap I see, without feeling guilty for not having actually watched it to see if it was any good or not.