You can never make everyone happy with timing, personally I hate drops/sales that start during the middle of the day on a work day, but stores do it all the time. So you either skip work, leave work (no personal electronics allowed in the entire building I work in) and try and snag something on a cell phone, or you risk your job using company resources for online shopping.
If you happen to have to work Friday, some might have been happy to have the deals show up on their day off when they can actually partake. It's the same with sales that start at midnight, some people work overnight shifts, so they get screwed, some of us simply won't stay up till 3am for a deal (for those PST midnight drops in EST.
I will say 3pm on Thanksgiving day or 6pm EST, is pretty shitty timing that's right in prime thanksgiving dinner time for families in any time zone. Make it 10am, 8pm etc. However, plenty of sites dropped stuff at midnight PST-EST last night and that's also shitty timing if you ask me. Who knows why, hoping for less web traffic, or just want to eliminate those that won't really "work" for the deals.