I would say that it is more about distrust than hate. It is just hard to trust Spektrum, especially with high value models, given their track record.
How about a little history...
Spektrum was first to market with their 2.4ghz systems, but it came at a heavy price in both their reputation and customer aircraft. DSM/2 was simplistic and not very robust. Their "Dual Link" "technology" randomly selects two free channels which could be adjacent which basically negates any advantage that using two frequencies would provide. Their DSM2 receivers went through multiple revisions to fix numerous problems ranging from "uncommanded elevator inputs" to the ridiculously long relink times.
When the full range DX7 was released, many people lost their planes due to poor low voltage performance of their RXs (a problem that persists today). Many people were still using 4 cell rx packs to power their electronics which often proved inadequate under load for the Spektrum RXs. Of course Spektrum's competitors don't seem to be as affected by these brownout issues, but it didn't stop Spektrum from pulling crap like this
. Then there was the DX8 - probably one of the worst tx launches ever with numerous hardware and software problems.
People will say that since Spektrum has more users, there are more complaints. There is some truth to this, but one just has to look at the sheer number of service bulletins that Spektrum has had to put out for its radios and receivers. Compare that with their competitors. Of course, every manufacturer has had problems, but not to the degree that Spektrum has had.
Instead of improving their underlying technology, Spektrum rather slap on more band-aids in the form of extra satellites, flashing LEDs, flight log data, and diversity TX antennas. Then there are the quality control issues such as bad trim switches, poor quality pots, pots with faulty connectors (how did this get by testing?
), faulty LCDs, etc.
Spektrum gambled and given their market penetration, it was probably a financial win, but it is going to take a long time for Spektrum to rehabilitate its reputation. And, I don't know if they will ever be taken seriously as a high-end manufacturer.
Essentially, Spektrum does not have a track record that engenders trust.