It's also meant to be humorous on a meta level, as Ben's teenage actor and Ami's English voice actor in the 2010's have also voiced Sasuke and Sakura respectively.
In later years, Ben had started getting paired with Ami Mizuno, Sailor Mercury, in a sort of Opposites Attract manner.Ben 10/Generator Rex: Heroes United made Ben/Rex shippers instantly, with the jacket scene being the most notable evidence.Crossover Ship: Both Ben and Gwen, especially as the sequel went on, became popular characters for pairing with others not from the Ben 10 franchise.There's also many who wanted a sequel to Omniverse instead of a reboot, especially with the former ending's Sequel Hook that sounded really promising. Others accused the reboot of being an attempt to draw more cash out of what was already a large Cash Cow Franchise (merchandise has sold over four billions at least), and hated the art-style, saying Ben looked a lot younger than 10 and more cartoonish. Some fans were happy, saying the show was best when the main characters were 10-year-old Ben, Gwen, and Grandpa Max, that the franchise had suffered so many Retcons that a reboot was needed, and that the reboot would likely bring over things people liked about the sequels in a more organic way.
Those for the more mature series feel that the mature tone was natural since the audience was growing up with the franchise, gave more opportunity for Character Development, and that the later attempts to change the tone back to the original series hampered the franchise and was ultimately what caused the reboot. There are those who liked the original series and Omniverse for their charm and felt that the more serious tone of Alien Force and Ultimate Alien was unfitting for the franchise.
The different tones of each series naturally caused a huge divide on which was better.