As good as Bonk's Revenge was it didn't have that "hook" that set it apart from other platformers the way SMW had different moves, cape, Yoshi. The thing that set Sonic apart from the others was that it was so damn fast.
I disagree with this. Bonk certainly had a hook-- how many other platformers had characters running around bonking things, performing jump spins, head dives, etc? I can honestly say, as a kid back in those days, it certainly was appealing and interesting enough to me! I thought the Bonk premise was way more intriguing than a blue hedgehog that didn't really do anything at all except have "tude."
The REAL problem wasn't the nonexistence of a strong mascot character, it was a lack of focus and mis-marketing.
a) Bonk as a mascot was introduced too late. This didn't necessarily have to have been fatal, but it was, because:
b) NEC didn't have a strong advertising campaign backing Bonk. The day Bonk's Adventure was released, new TG-16s should have started shipping with Bonk in place of Keith Courage as the pack-in. There should have been a filibuster-style TV (and other media) ad campaign featuring Bonk and the TG-16 that started as soon as the game was released. This was an area that SEGA got right. I still, to this day, remember SEGA and Sonic commercials with that annoying but undeniably infectious "SEGA!" yell. I don't remember any TG-16 commercials, at all, and I actually owned the system at the time!
c) NEC didn't know what the f*ck it was doing mascot-wise. NEC had no confidence in their own mascot; how could they expect consumers to? A year or so after Sonic, they decided Bonk wasn't good enough so they quietly switched him out for Zonk as the "official mascot" of the system. Sonic didn't really do anything except run fast but he had "tude" and he was outselling Bonk so NEC must have figured they needed their own mascot to do the same. Enter Zonk. Huge mistake, not that by this point there was anything they could have done to rectify the situation. What other success console actually had a mascot change MID-LIFE? This reeks of desperation, and by this time had any potential buyers been actually still paying attention, would've served as a huge deterrent.
What they failed to realize was Bonk was fine as a mascot, it was their marketing strategy (or lack thereof) that had issues. Only people that actually owned the system and were already familiar with the TG-16 even knew Bonk was the console mascot. Feeble and inadequate marketing created a situation where NEC's console didn't have a "face" in the eyes of potential buyers, but nobody could forget the "SEGA!" yell and that blue hedgehog that was always hanging around. Nintendo had it easiest, they didn't even need to do a damn thing. By 1990/1991 Mario games were selling themselves; he'd effectively established himself as the Nintendo mascot years earlier.
No, there is (was) nothing wrong with Bonk as the face of the TurboGrafx, but there was certainly something wrong with NEC.